1 4435 122 MOLECULAR DYSREGULATIONS UNDERLYING THE PATHOGENESIS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A CRIPPLING DISEASE CHARACTERIZED BY THE PRESENCE OF ENDOMETRIUM-LIKE TISSUE OR SCAR OUTSIDE THE UTERINE CAVITY, COMMONLY CONFINED TO THE PERITONEAL AND SEROSAL SURFACES OF THE PELVIC ORGANS. 10-15% OF WOMEN IN REPRODUCTIVE AGE ARE ESTIMATED TO BE AFFECTED BY ENDOMETRIOSIS. MOST OF THESE PATIENTS PRESENT WITH INFERTILITY AND SUFFER FROM PELVIC PAIN. THE BENIGN DISEASE RARELY PROGRESSES TO MALIGNANCY. REGARDLESS OF ITS HIGH PREVALENCE, THE PATHOGENESIS OF THE DISEASE IS NOT FULLY UNDERSTOOD. TREATMENT OPTIONS FOR ENDOMETRIOSIS ARE LIMITED AND ARE OFTEN BASED ON A SYMPTOMATIC APPROACH. THE UNAVAILABILITY OF PROPER DIAGNOSTIC APPROACHES, FEWER THERAPEUTIC OPTIONS, AND SPARSE UNDERSTANDING OF MOLECULAR ALTERATIONS ARE RESPONSIBLE FOR THE CONTINUED DISEASE BURDEN. EXPLORING THE MOLECULAR ELEMENTS CAUSING THE PATHOGENESIS OF ENDOMETRIOSIS MAY LEAD TO A NUMBER OF BREAKTHROUGHS IN THE TREATMENT OF THE ILLNESS, SUCH AS THE DISCOVERY OF NEW BIOMARKERS FOR DIAGNOSIS AND THERAPEUTIC TARGETS THAT CAN BE A GUIDE TO BETTER PROGNOSIS AND REDUCED RECURRENCE. THE GOAL OF THIS REVIEW IS TO PROVIDE THE READER A CRITICAL UNDERSTANDING OF THE DISEASE BY SUMMARIZING THE GENETIC, IMMUNOLOGICAL, HORMONAL, AND EPIGENETIC DEREGULATIONS THAT SUPPORT THE MOLECULAR BASIS FOR DEVELOPMENT OF ENDOMETRIOTIC CYST, WITH A SPECIAL FOCUS ON THE STUDY MODELS NEEDED TO ANALYZE THESE CHANGES IN THE ENDOMETRIOTIC MICROENVIRONMENT. 2021 2 5378 29 RECENT INSIGHTS ON THE GENETICS AND EPIGENETICS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A GYNECOLOGIC DISEASE AFFECTING UP TO 10% OF THE WOMEN AND A MAJOR CAUSE OF PAIN AND INFERTILITY. IT IS CHARACTERIZED BY THE IMPLANTATION OF FUNCTIONAL ENDOMETRIAL TISSUE AT ECTOPIC POSITIONS GENERALLY WITHIN THE PERITONEUM. THIS COMPLEX DISEASE HAS AN IMPORTANT GENETIC COMPONENT WITH A HERITABILITY ESTIMATED AT AROUND 50%. THIS REVIEW AIMS AT PROVIDING RECENT INSIGHTS INTO THE GENETIC BASES OF ENDOMETRIOSIS, AND PRESENTS A DETAILED OVERVIEW OF EVIDENCE OF EPIGENETIC ALTERATIONS SPECIFIC TO THIS DISEASE. IN THE FUTURE, THESE ALTERATIONS MAY CONSTITUTE THERAPEUTIC TARGETS FOR PHARMACOLOGICAL COMPOUNDS ABLE TO MODIFY THE EPIGENETIC CODE. 2017 3 1028 43 CIRCULATING MIRNAS RELATED TO EPITHELIAL-MESENCHYMAL TRANSITIONS (EMT) AS THE NEW MOLECULAR MARKERS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE DEFINED BY THE PRESENCE OF ENDOMETRIAL-LIKE TISSUE FOUND OUTSIDE THE UTERUS, MOST COMMONLY IN THE PERITONEAL CAVITY. ENDOMETRIOSIS LESIONS ARE HETEROGENOUS BUT USUALLY CONTAIN ENDOMETRIAL STROMAL CELLS AND EPITHELIAL GLANDS, IMMUNE CELL INFILTRATES AND ARE VASCULARIZED AND INNERVATED BY NERVES. THE COMPLEX ETIOPATHOGENESIS AND HETEROGENITY OF THE CLINICAL SYMPTOMS, AS WELL AS THE LACK OF A SPECIFIC NON-INVASIVE DIAGNOSTIC BIOMARKERS, UNDERLINE THE NEED FOR MORE ADVANCED DIAGNOSTIC TOOLS. UNFORTUNATELY, THE CONTRIBUTION OF ENVIRONMENTAL, HORMONAL AND IMMUNOLOGICAL FACTORS IN THE DISEASE ETIOLOGY IS INSUFFICIENT, AND THE CONTRIBUTION OF GENETIC/EPIGENETIC FACTORS IS STILL FRAGMENTARY. THEREFORE, THERE IS A NEED FOR MORE FOCUSED STUDY ON THE MOLECULAR MECHANISMS OF ENDOMETRIOSIS AND NON-INVASIVE DIAGNOSTIC MONITORING SYSTEMS. MICRORNAS (MIRNAS) DEMONSTRATE HIGH STABILITY AND TISSUE SPECIFICITY AND PLAY A SIGNIFICANT ROLE IN MODULATING A RANGE OF MOLECULAR PATHWAYS, AND HENCE MAY BE SUITABLE DIAGNOSTIC BIOMARKERS FOR THE ORIGIN AND DEVELOPMENT OF ENDOMETRIOSIS. OF THESE, THE MOST FREQUENTLY STUDIED ARE THOSE RELATED TO ENDOMETRIOSIS, INCLUDING THOSE INVOLVED IN EPITHELIAL-MESENCHYMAL TRANSITION (EMT), WHOSE EXPRESSION IS ALTERED IN PLASMA OR ENDOMETRIOTIC LESION BIOPSIES; HOWEVER, THE RESULTS ARE AMBIGUOUS. SPECIFIC MIRNAS EXPRESSED IN ENDOMETRIOSIS MAY SERVE AS DIAGNOSTICS MARKERS WITH PROGNOSTIC VALUE, AND THEY HAVE BEEN PROPOSED AS MOLECULAR TARGETS FOR TREATMENT. THE AIM OF THIS REVIEW IS TO PRESENT SELECTED MIRNAS ASSOCIATED WITH EMT KNOWN TO HAVE EXPERIMENTALLY CONFIRMED SIGNIFICANCE, AND DISCUSS THEIR UTILITY AS BIOMARKERS IN ENDOMETRIOSIS. 2021 4 3005 38 GENETIC, EPIGENETIC, AND STEROIDOGENIC MODULATION MECHANISMS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE, AFFECTING UP TO 10% OF REPRODUCTIVE-AGE WOMEN. THE EXACT CAUSE OF THE DISEASE IS UNKNOWN; HOWEVER, IT IS A HERITABLE CONDITION AFFECTED BY MULTIPLE GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. PREVIOUS STUDIES REPORTED VARIATIONS IN THE EPIGENETIC PATTERNS OF NUMEROUS GENES KNOWN TO BE INVOLVED IN THE ABERRANT MODULATION OF CELL CYCLE STEROIDOGENESIS, ABNORMAL HORMONAL, IMMUNE AND INFLAMMATORY STATUS IN ENDOMETRIOSIS, APOPTOSIS, ADHESION, ANGIOGENESIS, PROLIFERATION, IMMUNE AND INFLAMMATORY PROCESSES, RESPONSE TO HYPOXIA, STEROIDOGENIC PATHWAY AND HORMONE SIGNALING ARE INVOLVED IN THE PATHOGENESIS OF ENDOMETRIOSIS. ACCUMULATING EVIDENCE SUGGEST THAT VARIOUS EPIGENETIC ABERRATIONS MAY CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. AMONG THEM, DNA METHYLTRANSFERASES, HISTONE DEACETYLATORS, AND NON-CODING MICRORNAS DEMONSTRATE DIFFERENTIAL EXPRESSION WITHIN ENDOMETRIOTIC LESIONS AND IN THE ENDOMETRIUM OF PATIENTS WITH ENDOMETRIOSIS. IT HAS BEEN INDICATED THAT THE IDENTIFICATION OF EPIGENETIC DIFFERENCES WITHIN THE DNA OR HISTONE PROTEINS MAY CONTRIBUTE TO THE DISCOVERY OF A USEFUL PROGNOSTIC BIOMARKER, WHICH COULD AID IN THE FUTURE EARLIER DETECTION, TIMELY DIAGNOSIS, AND INITIATION OF A NEW APPROACH TO THE TREATMENT OF ENDOMETRIOSIS, AS WELL AS INFORM US ABOUT THE EFFECTIVENESS OF TREATMENT AND THE STAGE OF THE DISEASE. AS THE ETIOLOGY OF ENDOMETRIOSIS IS HIGHLY COMPLEX AND STILL FAR FROM BEING FULLY ELUCIDATED, THE PRESENTED REVIEW FOCUSES ON DIFFERENT APPROACHES TO IDENTIFY THE GENETIC AND EPIGENETIC LINKS OF ENDOMETRIOSIS AND ITS PATHOGENESIS. 2020 5 4956 37 PATHOGENESIS OF ENDOMETRIOSIS: FOCUS ON ADENOGENESIS-RELATED FACTORS. ENDOMETRIOSIS CAN BE DEFINED AS THE PRESENCE OF THE ENDOMETRIUM OUTSIDE THE UTERINE CAVITY. IT AFFECTS APPROXIMATELY 10% OF WOMEN OF REPRODUCTIVE AGE AND CAUSES INFERTILITY, CHRONIC PAIN, AND DETERIORATION OF THE QUALITY OF LIFE. SINCE THE IDENTIFICATION OF THE DISEASE, VARIOUS PATHOGENETIC MECHANISMS HAVE BEEN PROPOSED, SUCH AS RETROGRADE MENSTRUATION, COELOMIC METAPLASIA, HORMONAL IMBALANCE, STEM CELL INVOLVEMENT, AND ALTERATIONS IN EPIGENETIC REGULATION. HOWEVER, THE UNDERLYING PATHOGENESIS OF ENDOMETRIOSIS REMAINS INADEQUATELY UNDERSTOOD. ELUCIDATION OF THE PRECISE MECHANISM OF THE DEVELOPMENT AND PROGRESSION OF ENDOMETRIOSIS IS CRUCIAL FOR EFFECTIVE TREATMENT. THIS REVIEW PRESENTS THE MAJOR PATHOGENETIC THEORIES OF ENDOMETRIOSIS BASED ON CURRENT RESEARCH STUDIES WITH A MAJOR FOCUS ON THE POTENTIAL ROLE OF UTERINE FACTORS. 2023 6 3003 48 GENETIC, EPIGENETIC AND STEM CELL ALTERATIONS IN ENDOMETRIOSIS: NEW INSIGHTS AND POTENTIAL THERAPEUTIC PERSPECTIVES. HUMAN ENDOMETRIUM IS A HIGHLY DYNAMIC TISSUE, UNDERGOING PERIODIC GROWTH AND REGRESSION AT EACH MENSTRUAL CYCLE. ENDOMETRIOSIS IS A FREQUENT CHRONIC PATHOLOGICAL STATUS CHARACTERIZED BY ENDOMETRIAL TISSUE WITH AN ECTOPIC LOCALIZATION, CAUSING PELVIC PAIN AND INFERTILITY AND A VARIABLE CLINICAL PRESENTATION. IN ADDITION, THERE IS WELL-ESTABLISHED EVIDENCE THAT, ALTHOUGH ENDOMETRIOSIS IS CONSIDERED BENIGN, IT IS ASSOCIATED WITH AN INCREASED RISK OF MALIGNANT TRANSFORMATION IN APPROXIMATELY 1.0% OF AFFECTED WOMEN, WITH THE INVOLVEMENT OF MULTIPLE PATHWAYS OF DEVELOPMENT. INCREASING EVIDENCE SUPPORTS A KEY CONTRIBUTION OF DIFFERENT STEM/PROGENITOR CELL POPULATIONS NOT ONLY IN THE CYCLIC REGENERATION OF EUTOPIC ENDOMETRIUM, BUT ALSO IN THE PATHOGENESIS OF AT LEAST SOME TYPES OF ENDOMETRIOSIS. EVIDENCE HAS ARISEN FROM EXPERIMENTS IN ANIMAL MODELS OF DISEASE THROUGH DIFFERENT KINDS OF ASSAYS (INCLUDING CLONOGENICITY, THE LABEL-RETAINING CELL APPROACH, THE ANALYSIS OF UNDIFFERENTIATION MARKERS), AS WELL AS FROM DESCRIPTIVE STUDIES ON ECTOPIC AND EUTOPIC TISSUE SAMPLES HARVESTED FROM AFFECTED WOMEN. CHANGES IN STEM CELL POPULATIONS IN ENDOMETRIOTIC LESIONS ARE ASSOCIATED WITH GENETIC AND EPIGENETIC ALTERATIONS, INCLUDING IMBALANCE OF MIRNA EXPRESSION, HISTONE AND DNA MODIFICATIONS AND CHROMOSOMAL ABERRATIONS. THE PRESENT SHORT REVIEW MAINLY SUMMARIZES THE LATEST OBSERVATIONS CONTRIBUTING TO THE CURRENT KNOWLEDGE REGARDING THE PRESENCE AND THE POTENTIAL CONTRIBUTION OF STEM/PROGENITOR CELLS IN EUTOPIC ENDOMETRIUM AND THE AETIOLOGY OF ENDOMETRIOSIS, TOGETHER WITH A REPORT OF THE MOST RECENTLY IDENTIFIED GENETIC AND EPIGENETIC ALTERATIONS IN ENDOMETRIOSIS. WE ALSO DESCRIBE THE POTENTIAL ADVANTAGES OF SINGLE CELL MOLECULAR PROFILING IN ENDOMETRIUM AND IN ENDOMETRIOTIC LESIONS. ALL THESE DATA CAN HAVE CLINICAL IMPLICATIONS AND PROVIDE A BASIS FOR NEW POTENTIAL THERAPEUTIC APPLICATIONS. 2014 7 6237 39 THE MAIN THEORIES ON THE PATHOGENESIS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A COMPLEX DISEASE, WHICH IS DEFINED BY ABNORMAL GROWTH OF ENDOMETRIAL TISSUE OUTSIDE THE UTERUS. IT AFFECTS ABOUT 10% OF WOMEN OF REPRODUCTIVE AGE ALL OVER THE WORLD. ENDOMETRIOSIS CAUSES SYMPTOMS THAT NOTABLY WORSEN PATIENT'S WELL-BEING-SUCH AS SEVERE PELVIC PAIN, DYSFUNCTION OF THE ORGANS OF PELVIC CAVITY, INFERTILITY AND SECONDARY MENTAL ISSUES. THE DIAGNOSIS OF ENDOMETRIOSIS IS QUITE OFTEN DELAYED BECAUSE OF NONSPECIFIC MANIFESTATIONS. SINCE THE DISEASE WAS DEFINED, SEVERAL DIFFERENT PATHOGENETIC PATHWAYS HAVE BEEN CONSIDERED, INCLUDING RETROGRADE MENSTRUATION, BENIGN METASTASIS, IMMUNE DYSREGULATION, COELOMIC METAPLASIA, HORMONAL DISBALANCE, INVOLVEMENT OF STEM CELLS AND ALTERATIONS IN EPIGENETIC REGULATION, BUT THE TRUE PATHOGENESIS OF ENDOMETRIOSIS REMAINS POORLY UNDERSTOOD. THE KNOWLEDGE OF THE EXACT MECHANISM OF THE ORIGIN AND PROGRESSION OF THIS DISEASE IS SIGNIFICANT FOR THE APPROPRIATE TREATMENT. THEREFORE, THIS REVIEW REPORTS THE MAIN PATHOGENETIC THEORIES OF ENDOMETRIOSIS BASED ON CURRENT STUDIES. 2023 8 2086 32 EPIGENETIC DYSREGULATION IN ENDOMETRIOSIS: IMPLICATIONS FOR PATHOPHYSIOLOGY AND THERAPEUTICS. ENDOMETRIOSIS IS A PREVALENT GYNECOLOGICAL CONDITION ASSOCIATED WITH PELVIC PAIN AND INFERTILITY. DESPITE MORE THAN A CENTURY OF RESEARCH, THE ETIOLOGY OF ENDOMETRIOSIS STILL ELUDES SCIENTIFIC CONSENSUS. THIS LACK OF CLARITY HAS RESULTED IN SUBOPTIMAL PREVENTION, DIAGNOSIS, AND TREATMENT OPTIONS. EVIDENCE OF GENETIC CONTRIBUTORS TO ENDOMETRIOSIS IS INTERESTING BUT LIMITED; HOWEVER, SIGNIFICANT PROGRESS HAS BEEN MADE IN RECENT YEARS IN IDENTIFYING EPIGENETIC ROLE IN THE PATHOGENESIS OF ENDOMETRIOSIS THROUGH CLINICAL STUDIES, IN VITRO CELL CULTURE EXPERIMENTS, AND IN VIVO ANIMAL MODELS. THE PREDOMINANT FINDINGS INCLUDE ENDOMETRIOSIS-RELATED DIFFERENTIAL EXPRESSION OF DNA METHYLTRANSFERASES AND DEMETHYLASES, HISTONE DEACETYLASES, METHYLTRANSFERASES, AND DEMETHYLASES, AND REGULATORS OF CHROMATIN ARCHITECTURE. THERE IS ALSO AN EMERGING ROLE FOR MIRNAS IN THE CONTROL OF EPIGENETIC REGULATORS IN THE ENDOMETRIUM AND ENDOMETRIOSIS. CHANGES IN THESE EPIGENETIC REGULATORS RESULT IN DIFFERENTIAL CHROMATIN ORGANIZATION AND DNA METHYLATION WITH CONSEQUENCES FOR GENE EXPRESSION INDEPENDENT OF A GENETIC SEQUENCE. EPIGENETICALLY ALTERED EXPRESSION OF GENES RELATED TO STEROID HORMONE PRODUCTION AND SIGNALING, IMMUNE REGULATION, AND ENDOMETRIAL CELL IDENTITY AND FUNCTION HAVE ALL BEEN IDENTIFIED AND APPEAR TO PLAY INTO THE PATHOPHYSIOLOGICAL MECHANISMS OF ENDOMETRIOSIS AS WELL AS RESULTING INFERTILITY. THIS REVIEW SUMMARIZES AND CRITICALLY DISCUSSES EARLY SEMINAL FINDINGS, THE EVER-GROWING RECENT EVIDENCE OF EPIGENETIC CONTRIBUTIONS TO THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS, AND IMPLICATIONS FOR PROPOSED EPIGENETICALLY TARGETED THERAPEUTICS. 2023 9 5892 33 SYSTEMS GENETICS VIEW OF ENDOMETRIOSIS: A COMMON COMPLEX DISORDER. ENDOMETRIOSIS IS A CONDITION IN WHICH CELLS DERIVED FROM THE ENDOMETRIUM GROW OUTSIDE THE UTERUS, E.G. IN THE PERITONEUM (EXTERNAL GENITAL ENDOMETRIOSIS). AS THESE CELLS ARE UNDER THE INFLUENCE OF FEMALE HORMONES, MAJOR SYMPTOMS OF ENDOMETRIOSIS ARE PAIN, ESPECIALLY DURING THE CYCLE, AND INFERTILITY. NUMEROUS HYPOTHESES FOR THE FORMATION OF ENDOMETRIOSIS CAN BE FOUND IN THE LITERATURE, BUT THERE IS GROWING EVIDENCE OF SERIOUS GENETIC CONTRIBUTIONS TO ENDOMETRIOSIS SUSCEPTIBILITY. THE INVOLVEMENT OF GENES, STEROID HORMONE METABOLISM, IMMUNOLOGICAL REACTIONS, RECEPTOR FORMATION, INFLAMMATION, PROLIFERATION, APOPTOSIS, INTERCELLULAR ADHESION, CELL INVASION AND ANGIOGENESIS AS WELL AS GENES REGULATING THE ACTIVITY OF AFOREMENTIONED ENZYMES HAVE BEEN SUGGESTED. SOME MORE RECENTLY SUGGESTED CANDIDATE GENES PICKED UP IN GENOME-WIDE ASSOCIATION STUDIES ARE INVOLVED IN ONCOGENESIS, METAPLASIA OF ENDOMETRIUM CELLS AND PATHWAYS OF EMBRYONIC DEVELOPMENT OF THE FEMALE REPRODUCTIVE SYSTEM. HOWEVER, GENE MUTATIONS PROVEN TO BE CAUSATIVE FOR ENDOMETRIOSIS HAVE NOT BEEN IDENTIFIED SO FAR, EVEN THOUGH THE ABNORMAL EXPRESSION OF CANDIDATE GENES FOR ENDOMETRIOSIS COULD BE PROVOKED BY DIFFERENT EPIGENETIC MODIFICATIONS INCLUDING DNA METHYLATION, HETEROCHROMATIZATION OR INTRODUCTION OF REGULATORY MIRNA. WE HYPOTHESIZE THAT ENDOMETRIOSIS IS INDUCED BY A COMBINATION OF ABNORMAL GENETIC AND/OR EPIGENETIC MUTATIONS: THE LATTER PAVE THE WAY FOR PATHOLOGICAL CHANGES WHICH BECOME IRREVERSIBLE, AND ACCORDING TO THE "EPIGENETIC LANDSCAPE" THEORY, THIS PROCEEDS TO THE TYPICAL CLINICAL MANIFESTATIONS. TWO STAGES IN THE ENDOMETRIOSIS PATHWAY ARE SUGGESTED: (1) INDUCTION OF PRIMARY ENDOMETRIAL CELLS TOWARD ENDOMETRIOSIS, AND (2) IMPLANTATION AND PROGRESSION OF THESE CELLS INTO ENDOMETRIOSIS LESIONS. THE MODEL FAVORS ENDOMETRIOSIS AS AN OUTGROWTH OF PRIMARY CELLS DIFFERENT IN THEIR ORIGIN, CANALIZATION OF PATHOLOGICAL PROCESSES, MANIFESTATION DIVERSITY PROVOKED BY UNIQUE GENETIC BACKGROUND AND EPIGENETIC INFLUENCES, WHICH RESULT IN MANY DIFFERENT CLINICAL FORMS OF THE DISEASE. 2015 10 506 35 ASSOCIATION OF ENDOMETRIOSIS WITH CARDIOVASCULAR DISEASE: GENETIC ASPECTS (REVIEW). CARDIOVASCULAR DISEASE (CVD) COMPRISES A BROAD SPECTRUM OF PATHOLOGICAL CONDITIONS THAT AFFECT THE HEART OR BLOOD VESSELS, INCLUDING SEQUELAE THAT ARISE FROM DAMAGED VASCULATURE IN OTHER ORGANS OF THE BODY, SUCH AS THE BRAIN, KIDNEYS OR EYES. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE OF THE ARTERIAL INTIMA AND IS THE PRIMARY CAUSE OF CORONARY ARTERY DISEASE, PERIPHERAL VASCULAR DISEASE, HEART ATTACK, STROKE AND RENAL PATHOLOGY. IT REPRESENTS A LEADING CAUSE OF MORTALITY WORLDWIDE AND THE LOSS OF HUMAN PRODUCTIVITY THAT IS MARKED BY AN ALTERED IMMUNE RESPONSE. ENDOMETRIOSIS IS A HERITABLE, HETEROGENEOUS, COMMON GYNECOLOGICAL CONDITION INFLUENCED BY MULTIPLE GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS, AFFECTING UP TO 10% OF THE FEMALE POPULATION OF CHILDBEARING AGE, CAUSING PAIN AND INFERTILITY; IT IS CHARACTERIZED BY THE ECTOPIC GROWTH OF ENDOMETRIAL TISSUE OUTSIDE THE UTERINE CAVITY. OF NOTE, EPIDEMIOLOGICAL DATA OBTAINED THUS FAR HAVE SUGGESTED A LINK BETWEEN ENDOMETRIOSIS AND THE RISK OF DEVELOPING CVD. THE SIMILARITIES OBSERVED IN SPECIFIC MOLECULAR AND CELLULAR PATHWAYS OF ENDOMETRIOSIS AND CVD MAY BE PARTIALLY EXPLAINED BY A SHARED GENETIC BACKGROUND. THE PRESENT REVIEW PRESENTS AND DISCUSSES THE SHARED GENETIC FACTORS WHICH HAVE BEEN REPORTED TO BE ASSOCIATED WITH THE DEVELOPMENT OF BOTH DISORDERS. 2023 11 2275 44 EPIGENETIC REGULATION AND T-CELL RESPONSES IN ENDOMETRIOSIS - SOMETHING OTHER THAN AUTOIMMUNITY. ENDOMETRIOSIS IS DEFINED AS THE PRESENCE OF ENDOMETRIAL-LIKE GLANDS AND STROMA LOCATED OUTSIDE THE UTERINE CAVITY. THIS COMMON, ESTROGEN DEPENDENT, INFLAMMATORY CONDITION AFFECTS UP TO 15% OF REPRODUCTIVE-AGED WOMEN AND IS A WELL-RECOGNIZED CAUSE OF CHRONIC PELVIC PAIN AND INFERTILITY. DESPITE THE STILL UNKNOWN ETIOLOGY OF ENDOMETRIOSIS, MUCH EVIDENCE SUGGESTS THE PARTICIPATION OF EPIGENETIC MECHANISMS IN THE DISEASE ETIOPATHOGENESIS. THE MAIN RATIONALE IS BASED ON THE FACT THAT HERITABLE PHENOTYPE CHANGES THAT DO NOT INVOLVE ALTERATIONS IN THE DNA SEQUENCE ARE COMMON TRIGGERS FOR HORMONAL, IMMUNOLOGICAL, AND INFLAMMATORY DISORDERS, WHICH PLAY A KEY ROLE IN THE FORMATION OF ENDOMETRIOTIC FOCI. EPIGENETIC MECHANISMS REGULATING T-CELL RESPONSES, INCLUDING DNA METHYLATION AND POSTTRANSLATIONAL HISTONE MODIFICATIONS, DESERVE ATTENTION BECAUSE TISSUE-RESIDENT T LYMPHOCYTES WORK IN CONCERT WITH ORGAN STRUCTURAL CELLS TO GENERATE APPROPRIATE IMMUNE RESPONSES AND ARE FUNCTIONALLY SHAPED BY ORGAN-SPECIFIC ENVIRONMENTAL CONDITIONS. THUS, A FAILURE TO PRECISELY REGULATE IMMUNE CELL TRANSCRIPTION MAY RESULT IN COMPROMISED IMMUNOLOGICAL INTEGRITY OF THE ORGAN WITH AN INCREASED RISK OF INFLAMMATORY DISORDERS. THE COEXISTENCE OF ENDOMETRIOSIS AND AUTOIMMUNITY IS A WELL-KNOWN OCCURRENCE. RECENT RESEARCH RESULTS INDICATE REGULATORY T-CELL (TREG) ALTERATIONS IN ENDOMETRIOSIS, AND AN INCREASED NUMBER OF HIGHLY ACTIVE TREGS AND MACROPHAGES HAVE BEEN FOUND IN PERITONEAL FLUID FROM WOMEN WITH ENDOMETRIOSIS. ELIMINATION OF THE REGULATORY FUNCTION OF T CELLS AND AN IMBALANCE BETWEEN T HELPER CELLS OF THE TH1 AND TH2 TYPES HAVE BEEN REPORTED IN THE ENDOMETRIA OF WOMEN WITH ENDOMETRIOSIS-ASSOCIATED INFERTILITY. THIS REVIEW AIMS TO PRESENT THE STATE OF THE ART IN RECOGNITION EPIGENETIC REPROGRAMMING OF T CELLS AS THE KEY FACTOR IN THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS IN THE CONTEXT OF T-CELL-RELATED AUTOIMMUNITY. THE NEW POTENTIAL THERAPEUTIC APPROACHES BASED ON EPIGENETIC MODULATION AND/OR ADOPTIVE TRANSFER OF T CELLS WILL ALSO BE OUTLINED. 2022 12 1889 30 ENDOMETRIOSIS MALIGNANT TRANSFORMATION: EPIGENETICS AS A PROBABLE MECHANISM IN OVARIAN TUMORIGENESIS. ENDOMETRIOSIS, DEFINED AS THE PRESENCE OF ECTOPIC ENDOMETRIAL GLANDS AND STROMA OUTSIDE THE UTERINE CAVITY, IS A CHRONIC, HORMONE-DEPENDENT GYNECOLOGIC DISEASE AFFECTING MILLIONS OF WOMEN ACROSS THE WORLD, WITH SYMPTOMS INCLUDING CHRONIC PELVIC PAIN, DYSMENORRHEA, DYSPAREUNIA, DYSURIA, AND SUBFERTILITY. IN ADDITION, THERE IS WELL-ESTABLISHED EVIDENCE THAT, ALTHOUGH ENDOMETRIOSIS IS CONSIDERED BENIGN, IT IS ASSOCIATED WITH AN INCREASED RISK OF MALIGNANT TRANSFORMATION, WITH THE INVOLVEMENT OF VARIOUS MECHANISMS OF DEVELOPMENT. MORE AND MORE EVIDENCE REVEALS AN IMPORTANT CONTRIBUTION OF EPIGENETIC MODIFICATION NOT ONLY IN ENDOMETRIOSIS BUT ALSO IN MECHANISMS OF ENDOMETRIOSIS MALIGNANT TRANSFORMATION, INCLUDING DNA METHYLATION AND DEMETHYLATION, HISTONE MODIFICATIONS, AND MIRNA ABERRANT EXPRESSIONS. IN THIS PRESENT REVIEW, WE MAINLY SUMMARIZE THE RESEARCH PROGRESS ABOUT THE CURRENT KNOWLEDGE REGARDING THE EPIGENETIC MODIFICATIONS OF THE RELATIONS BETWEEN ENDOMETRIOSIS MALIGNANT TRANSFORMATION AND OVARIAN CANCER IN AN EFFORT TO IDENTIFY SOME RISK FACTORS PROBABLY ASSOCIATED WITH ECTOPIC ENDOMETRIUM TRANSFORMATION. 2018 13 4957 33 PATHOGENESIS OF ENDOMETRIOSIS: THE GENETIC/EPIGENETIC THEORY. OBJECTIVE: TO STUDY THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS. DESIGN: OVERVIEW OF OBSERVATIONS ON ENDOMETRIOSIS. SETTING: NOT APPLICABLE. PATIENT(S): NONE. INTERVENTIONS(S): NONE. MAIN OUTCOME MEASURE(S): THE HYPOTHESIS IS COMPATIBLE WITH ALL OBSERVATIONS. RESULT(S): ENDOMETRIOSIS, ENDOMETRIUM-LIKE TISSUE OUTSIDE THE UTERUS, HAS A VARIABLE MACROSCOPIC APPEARANCE AND A POORLY UNDERSTOOD NATURAL HISTORY. IT IS A HEREDITARY AND HETEROGENEOUS DISEASE WITH MANY BIOCHEMICAL CHANGES IN THE LESIONS, WHICH ARE CLONAL IN ORIGIN. IT IS ASSOCIATED WITH PAIN, INFERTILITY, ADENOMYOSIS, AND CHANGES IN THE JUNCTIONAL ZONE, PLACENTATION, IMMUNOLOGY, PLASMA, PERITONEAL FLUID, AND CHRONIC INFLAMMATION OF THE PERITONEAL CAVITY. THE SAMPSON HYPOTHESIS OF IMPLANTED ENDOMETRIAL CELLS FOLLOWING RETROGRADE MENSTRUATION, ANGIOGENIC SPREAD, LYMPHOGENIC SPREAD, OR THE METAPLASIA THEORY CANNOT EXPLAIN ALL OBSERVATIONS IF METAPLASIA IS DEFINED AS CELLS WITH REVERSIBLE CHANGES AND AN ABNORMAL BEHAVIOR/MORPHOLOGY DUE TO THE ABNORMAL ENVIRONMENT. WE PROPOSE A POLYGENETIC/POLYEPIGENETIC MECHANISM. THE SET OF GENETIC AND EPIGENETIC INCIDENTS TRANSMITTED AT BIRTH COULD EXPLAIN THE HEREDITARY ASPECTS, THE PREDISPOSITION, AND THE ENDOMETRIOSIS-ASSOCIATED CHANGES IN THE ENDOMETRIUM, IMMUNOLOGY, AND PLACENTATION. TO DEVELOP TYPICAL, CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS, A VARIABLE SERIES OF ADDITIONAL TRANSMISSIBLE GENETIC AND EPIGENETIC INCIDENTS ARE REQUIRED TO OCCUR IN A CELL WHICH MAY VARY FROM ENDOMETRIAL TO STEM CELLS. SUBTLE LESIONS ARE VIEWED AS ENDOMETRIUM IN A DIFFERENT ENVIRONMENT UNTIL ADDITIONAL INCIDENTS OCCUR. TYPICAL CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS ARE HETEROGENEOUS AND REPRESENT THREE DIFFERENT DISEASES. CONCLUSION(S): THE GENETIC EPIGENETIC THEORY IS COMPATIBLE WITH ALL OBSERVATIONS ON ENDOMETRIOSIS. IMPLICATIONS FOR TREATMENT AND PREVENTION ARE DISCUSSED. 2019 14 1249 22 CURRENT KNOWLEDGE ON ENDOMETRIOSIS ETIOLOGY: A SYSTEMATIC REVIEW OF LITERATURE. OBJECTIVE: TO REVIEW THE MECHANISMS OF ENDOMETRIOSIS DEVELOPMENT, INCLUDING THOSE RELATED TO EPIGENETIC MUTATIONS, CELLULAR DYSREGULATION, INFLAMMATORY PROCESSES, AND OXIDATIVE STRESS. METHODS: A SYSTEMATIC LITERATURE REVIEW REGARDING CURRENT ASPECTS OF ENDOMETRIOSIS ETIOLOGY, GENESIS AND DEVELOPMENT WAS PERFORMED USING THE PUBMED, GOOGLE SCHOLAR, AND ELIBRARY DATABASES. KEYWORDS INCLUDED ENDOMETRIOSIS, ETIOLOGY, DEVELOPMENT, GENESIS, ASSOCIATIONS AND MECHANISMS. A MULTILINGUAL SEARCH WAS PERFORMED. RESULTS: SEVERAL MECHANISMS UNDERLINE THE PATHOPHYSIOLOGICAL PATHWAYS FOR ENDOMETRIOSIS DEVELOPMENT. EPIGENETIC MUTATIONS, EXTERNAL AND INTERNAL INFLUENCES, AND CHRONIC CONDITIONS HAVE A SIGNIFICANT IMPACT ON ENDOMETRIOSIS DEVELOPMENT, SURVIVAL AND REGULATION. SEVERAL HISTORICALLY VALID THEORIES ON ENDOMETRIOSIS DEVELOPMENT WERE DISCUSSED, AS WELL AS UPDATED FINDINGS. CONCLUSION: DESPITE RECENT ADVANCES, FUNDAMENTAL PROBLEMS IN UNDERSTANDING ENDOMETRIOSIS REMAIN UNRESOLVED. THE IDENTIFICATION OF UNKNOWN CIRCULATING EPITHELIAL PROGENITORS OR STEM CELLS THAT ARE RESPONSIBLE FOR EPITHELIAL GROWTH IN BOTH THE ENDOMETRIUM AND ENDOMETRIOTIC FOCI SEEMS TO BE THE NEXT STEP IN SOLVING THESE QUESTIONS. 2021 15 6796 33 [ENDOMETRIOSIS: A NEW APPROACH TO ETIOLOGY AND PATHOGENESIS (REVIEW)]. ENDOMETRIOSIS IS A DYSHORMONAL IMMUNE-DEPENDENT GENETICALLY DETERMINED DISEASE, WHICH APPEARS AS AN ENDOMETRIOID TISSUE THAT GROWS OUTSIDE THE UTERINE. ENDOMETRIOSIS IS ONE OF THE MOST URGENT PROBLEMS OF MEDICINE. TO DATE, NEW CONCEPTS OF THE ENDOMETRIOSIS ETIOLOGY AND PATHOGENESIS HAVE BEEN DEVELOPED, BUT, DESPITE THEIR ABUNDANCE, THERE IS NO UNIFIED THEORY. GENETIC AND EPIGENETIC FACTORS RESULT IN CHANGES IN AN EXPRESSION OF AROMATASE, STEROIDOGENIC FACTOR 1, AND ESTROGEN RECEPTORS ARE SUGGESTED TO BE THE MAIN CAUSE OF ENDOMETRIOSIS. THESE CHANGES LEAD TO AN ACTIVE SYNTHESIS OF VARIOUS PRO-INFLAMMATORY AGENTS AND A NERVE GROWTH FACTOR, THAT ARE IMPORTANT IN THE DEVELOPMENT OF PAIN SYNDROME. ALSO, CHANGES IN THE PROGESTERONE RECEPTOR FUNCTIONING AND THE LOCAL PROGESTERONE RESISTANCE DEVELOPMENT DECREASE THE ANTIPROLIFERATIVE ACTIVITY, APOPTOSIS, AND THE ANTI-INFLAMMATORY SUBSTANCES LEVEL, AS WELL AS INCREASE THE PROSTAGLANDIN, METALLOPROTEINASE ACTIVITY, AND LEVEL OF HYPOXIA FACTORS. IN ADDITION, THERE ARE SHREDS OF EVIDENCE THAT ENDOMETRIOSIS IS ASSOCIATED WITH THE RISK OF MALIGNANT TUMORS DEVELOPMENT, SO NEW CONCEPTS FOR UNDERSTANDING THESE MECHANISMS ARE ACTIVELY DEVELOPING. SOME OF THESE MECHANISMS ARE DISCUSSED IN THIS REVIEW. 2017 16 1893 44 ENDOMETRIOSIS: NEW PERSPECTIVE FOR THE DIAGNOSIS OF CERTAIN CYTOKINES IN WOMEN AND ADOLESCENT GIRLS, AS WELL AS THE PROGRESSION OF DISEASE OUTGROWTH: A SYSTEMATIC REVIEW. ENDOMETRIOSIS IS A COMMON CHRONIC GYNECOLOGICAL DISORDER THAT UNDOUBTEDLY IMPACTS ON QUALITY OF LIFE, AND IS ONE OF THE MORE COMPLEX AND MYSTERIOUS ILLNESSES OF OUR CENTURY, WHICH IS ASSOCIATED WITH THE IMPROPER GROWTH OF ENDOMETRIAL TISSUE OUTSIDE OF THE UTERINE CAVITY. THIS PATHOLOGICALLY IMPLANTED TISSUE CAN BE FOUND MOST FREQUENTLY IN THE MINOR PELVIS, BUT ALSO IN THE PERITONEAL CAVITY, AND CAN AFFECT MANY ORGANS, LEADING TO CHRONIC PELVIC PAIN SYNDROME, INFERTILITY, AND DYSMENORRHEA. ENDOMETRIAL TISSUE IS A PARTICULARLY DYNAMIC TISSUE THAT HAS A DIRECT IMPACT ON THE PROGRESSION OF THE DISEASE, WITH ALTERED IMMUNITY, AS WELL AS CYTOKINE STORMS WITHIN THE METAPLASTIC ENDOMETRIOTIC SITE, AS POSSIBLE KEY FACTORS. CURRENTLY, DIAGNOSIS OF THIS MYSTERIOUS CHRONIC ILLNESS RELIES ON PERFORMING A LAPAROSCOPIC PROCEDURE WITH TISSUE SAMPLING. ONE OF THE MOST TROUBLESOME OUTCOMES OF THIS UNINTENDED PROGRESSION IS THAT WE LACK ANY SPECIFIC, SENSITIVE, NON-INVASIVE DIAGNOSTIC TOOLS. CURRENTLY, THE VAST MAJORITY OF REGIME STEWARDSHIP OPTIONS RELY ON ANTI-CONTRACEPTIVE DRUGS, OR OTHER REMEDIES THAT SUPPRESS THE RELEASE OF ESTROGEN THROUGH THE GONADS-ALTHOUGH IN MOST CLINICAL TRIALS, ENDOMETRIOSIS IS A CHRONIC PROGRESSIVE DISORDER THAT DEPENDS MOSTLY ON THE HIGH CONCENTRATION OF ESTROGEN. MOREOVER, MANY SPECIFIC TRIALS HAVE DEMONSTRATED THAT THE EUTOPIC ENDOMETRIAL CELLS IN INDIVIDUALS WITH ENDOMETRIOSIS REMAIN MUCH MORE RESISTANT TO THE IMMUNOLOGICAL ANNIHILATION PROCESS CAUSED BY CERTAIN ELEMENTS OF THE IMMUNE SYSTEM. NEVERTHELESS, EUTOPIC ENDOMETRIAL CELLS HAVE THE POTENTIAL TO SIMILARLY ESCALATE THE EXPRESSION OF AROMATASE RECEPTORS ON THE SURFACE OF THE PATHOLOGICAL CELLS, WHICH IN THE FINAL CASCADE CAUSE AN INCREASE IN THE CONCENTRATION OF ESTROGEN, AS WELL AS OTHER INFLAMMATORY PROTEINS THAT CONTRIBUTE TO PATHOLOGICAL OUTGROWTH. DATA REVEAL OCCURRENCE AMONG FIRST-DEGREE RELATIVES, SUGGESTING THAT THE SPECIFIC CASCADE COULD BE RELATED TO INHERITED AS WELL AS EPIGENETIC (ACQUIRED) MECHANISMS. IN WOMEN WITH THE DISEASE, CONFIRMED BY LAPAROSCOPIC PROCEDURES, DIAGNOSIS OF ENDOMETRIOSIS CAN BE ESTABLISHED ALSO VIA DETECTION BY GENE POLYMORPHISM IN THE GENES WHICH ARE RESPONSIBLE FOR RESPONSIBLE FOR THE DETOXIFICATION PHASE OF ESTROGEN RECEPTORS AND OTHER IMMUNOMODULATOR COMPONENTS. A RECENT PUBLICATION AIMS TO REVEAL A NEW PROSPECT FOR THE NON-INVASIVE DIAGNOSIS, DETECTION, AND ESTIMATION OF CERTAIN BIOMARKERS FOR MUCH MORE SPECIFIC INVESTIGATION OF THE DISEASE'S PROGRESSION. 2021 17 3821 37 INTRODUCTION: FROM PATHOGENESIS TO THERAPY, DEEP ENDOMETRIOSIS REMAINS A SOURCE OF CONTROVERSY. DEEP ENDOMETRIOSIS REMAINS A SOURCE OF CONTROVERSY. A NUMBER OF THEORIES MAY EXPLAIN ITS PATHOGENESIS AND MANY ARGUMENTS SUPPORT THE HYPOTHESIS THAT GENETIC OR EPIGENETIC CHANGES ARE A PREREQUISITE FOR DEVELOPMENT OF LESIONS INTO DEEP ENDOMETRIOSIS. DEEP ENDOMETRIOSIS IS FREQUENTLY RESPONSIBLE FOR PELVIC PAIN, DYSMENORRHEA, AND/OR DEEP DYSPAREUNIA, BUT CAN ALSO CAUSE OBSTETRICAL COMPLICATIONS. DIAGNOSIS MAY BE IMPROVED BY HIGH-QUALITY IMAGING. THERAPEUTIC APPROACHES ARE A SOURCE OF CONTENTION AS WELL. IN THIS ISSUE'S VIEWS AND REVIEWS, MEDICAL AND SURGICAL STRATEGIES ARE DISCUSSED, AND IT IS EMPHASIZED THAT TREATMENT SHOULD BE DESIGNED ACCORDING TO A PATIENT'S SYMPTOMS AND INDIVIDUAL NEEDS. IT IS ALSO VITAL THAT REFERRAL CENTERS HAVE THE KNOWLEDGE AND EXPERIENCE TO TREAT DEEP ENDOMETRIOSIS MEDICALLY AND/OR SURGICALLY. THE DEBATE MUST CONTINUE BECAUSE EMERGING TRENDS IN THERAPY NEED TO BE FOLLOWED AND INVESTIGATED FOR OPTIMAL MANAGEMENT. 2017 18 3108 25 GENOMICS OF PAIN IN OSTEOARTHRITIS. OSTEOARTHRITIS (OA) ACCOUNTS FOR THE MAJORITY OF THE DISEASE BURDEN FOR MUSCULOSKELETAL DISORDERS AND IS ONE OF THE LEADING CAUSES OF DISABILITY WORLDWIDE. THIS DISABILITY IS THE RESULT NOT OF THE CARTILAGE LOSS THAT DEFINES OA RADIOGRAPHICALLY, BUT OF THE CHRONIC PAIN WHOSE PRESENCE DEFINES SYMPTOMATIC OA. IT IS BECOMING CLEAR THAT MANY GENES, EACH WITH A SMALL EFFECT SIZE, CONTRIBUTE TO THE RISK OF DEVELOPING OA. HOWEVER, THE GENETICS OF OA PAIN ARE ONLY JUST STARTING TO BE EXPLORED. THIS REVIEW WILL DESCRIBE THE FIRST GENES TO HAVE BEEN IDENTIFIED IN GENOMIC STUDIES OF OA PAIN, AS WELL AS THE POSSIBLE DUAL ROLES OF GENES PREVIOUSLY IDENTIFIED IN GENOMIC STUDIES OF OA IN THE CONTEXT OF PAIN. DIFFICULTIES ASSOCIATED WITH ATTEMPTING TO CHARACTERISE THE GENETICS OF OA PAIN WILL BE DISCUSSED AND PROMISING FUTURE AVENUES OF RESEARCH INTO GENETIC AND EPIGENETIC FACTORS AFFECTING OA PAIN DESCRIBED. 2013 19 3038 40 GENOME ENGINEERING FOR OSTEOARTHRITIS: FROM DESIGNER CELLS TO DISEASE-MODIFYING DRUGS. BACKGROUND: OSTEOARTHRITIS (OA) IS A HIGHLY PREVALENT DEGENERATIVE JOINT DISEASE INVOLVING JOINT CARTILAGE AND ITS SURROUNDING TISSUES. OA IS THE LEADING CAUSE OF PAIN AND DISABILITY WORLDWIDE. AT PRESENT, THERE ARE NO DISEASE-MODIFYING OA DRUGS, AND THE PRIMARY THERAPIES INCLUDE EXERCISE AND NONSTEROIDAL ANTI-INFLAMMATORY DRUGS UNTIL TOTAL JOINT REPLACEMENT AT THE END-STAGE OF THE DISEASE. METHODS: IN THIS REVIEW, WE SUMMARIZED THE CURRENT STATE OF KNOWLEDGE IN GENETIC AND EPIGENETIC ASSOCIATIONS AND RISK FACTORS FOR OA AND THEIR POTENTIAL DIAGNOSTIC AND THERAPEUTIC APPLICATIONS. RESULTS: GENOME-WIDE ASSOCIATION STUDIES AND ANALYSIS OF EPIGENETIC MODIFICATIONS (SUCH AS MIRNA EXPRESSION, DNA METHYLATION AND HISTONE MODIFICATIONS) CONDUCTED ACROSS VARIOUS POPULATIONS SUPPORT THE NOTION THAT THERE IS A GENETIC BASIS FOR CERTAIN SUBSETS OF OA PATHOGENESIS. CONCLUSION: WITH RECENT ADVANCES IN THE DEVELOPMENT OF GENOME EDITING TECHNOLOGIES SUCH AS THE CRISPR-CAS9 SYSTEM, THESE GENETIC AND EPIGENETIC ALTERNATIONS IN OA CAN BE USED AS PLATFORMS FROM WHICH POTENTIAL BIOMARKERS FOR THE DIAGNOSIS, PROGNOSIS, DRUG RESPONSE, AND DEVELOPMENT OF POTENTIAL PERSONALIZED THERAPEUTIC TARGETS FOR OA CAN BE APPROACHED. FURTHERMORE, GENOME EDITING HAS ALLOWED THE DEVELOPMENT OF "DESIGNER" CELLS, WHEREBY THE RECEPTORS, GENE REGULATORY NETWORKS, OR TRANSGENES CAN BE MODIFIED AS A BASIS FOR NEW CELL-BASED THERAPIES. 2019 20 1892 25 ENDOMETRIOSIS: EPIDEMIOLOGY, CLASSIFICATION, PATHOGENESIS, TREATMENT AND GENETICS (REVIEW OF LITERATURE). ENDOMETRIOSIS IS A "MYSTERIOUS" DISEASE AND ITS EXACT CAUSE HAS NOT YET BEEN ESTABLISHED. AMONG THE ETIOLOGICAL FACTORS, CONGENITAL, ENVIRONMENTAL, EPIGENETIC, AUTOIMMUNE AND ALLERGIC FACTORS ARE LISTED. IT IS BELIEVED THAT THE PRIMARY MECHANISM OF THE FORMATION OF ENDOMETRIOSIS FOCI IS RETROGRADE MENSTRUATION, I.E., THE PASSAGE OF MENSTRUAL BLOOD THROUGH THE FALLOPIAN TUBES INTO THE PERITONEAL CAVITY AND IMPLANTATION OF EXFOLIATED ENDOMETRIAL CELLS. HOWEVER, SINCE THIS MECHANISM IS ALSO OBSERVED IN HEALTHY WOMEN, OTHER FACTORS MUST ALSO BE INVOLVED IN THE FORMATION OF ENDOMETRIOSIS FOCI. ENDOMETRIOSIS IS IN MANY WOMEN THE CAUSE OF INFERTILITY, CHRONIC PAIN AND THE DETERIORATION OF THE QUALITY OF LIFE. IT ALSO REPRESENTS A SIGNIFICANT FINANCIAL BURDEN ON HEALTH SYSTEMS. THE ARTICLE PRESENTS A REVIEW OF THE LITERATURE ON ENDOMETRIOSIS-A DISEASE AFFECTING WOMEN THROUGHOUT THE WORLD. 2021