子宫内膜异位症是严重影响育龄妇女健康及生育的常见病、多发病。课题组在该病的基础与临床研究过程中，形成了独到的病因学观点。即认为，内异症是由异常的子宫在位内膜组织随经血逆流至盆腹腔，在异地完成粘附、侵袭、血管形成之病理过程，而形成病灶。致病的关键系子宫在位内膜本身，而在位内膜干/祖细胞或其微环境的改变可能是根本原因。此外，内异症还表现出类肿瘤特质。上述病因学研究结果推进了临床诊疗技术和水平。近年来在位内膜标志物的检测和局部治疗更反映了“源头”诊疗的新观念。对内异症发病机制的再认识和新观念，直接影响了临床问题解决的新方向。

Endometriosis (EM) is one of the most common diseases which severely affect the health and reproductive function for women of childbearing age. Though the basic and clinical research in past decades, we have formed our unique and systemic opinion about the etiology of EM. The abnormal endometrial tissue in EM patients flows backward to abdominal and pelvic cavity, completes three-step procedure of attachment- aggression-angiogenesis, and ultimately develops into EM. In all variable influencing factors, including immune, inflammation or local micro-enviroment, the character of eutopic endometrium determines the fate of the backward-flowing endometrial tissue, live or die; for women, being ill or not. By further deeply exploring, the stem cell or its micro-enviroment in eutopic endometrium might play the key role. Besides, EM is considered as a tumor-like disorder. Our series of conceptions about EM pathogenesis could be summarized as "3A"  model, "eutopic endometrial determinant"  theory, and "stem cell origination"  hypothesis. All in all, the study about development mechanism of EM ultimately will help to find out the more efficient and sensitive method for diagnosis, and exploit much effective measure of treatment as well.