Endometrium, a heterogeneous tissue lining the uterus, is highly dynamic and exhibits marked cyclic changes during the menstrual cycle. Any aberration in endometrial physiology would lead to diseases like endometriosis, endometrial polyps, hyperplasia and endometrial cancer. The pathogenesis of endometriosis includes the proliferation of heterogeneous endometrial cells and their invasion into ectopic sites within the peritoneal cavity. This may be due to abnormalities of the eutopic endometrium itself, predisposing the cells to survive and implant ectopically. Several studies were carried out...