CYP19A1 and endometriosis: In view of their ability to inhibit estrogenbiosynthesis, third generation aromatase inhibitors(AIs) mainly letrozole and anastrozole have challenged clomiphene citrate (CC) in management ofinfertile patients with polycystic ovary syndromeas well as those with unexplained infertility (11).Additionally, the use of AIs to suppress the locallyproduced E2 by endometriotic deposits has gainedground as a potential therapy for correcting abnormal endocrine and reproductive function of patientswith endometriosis (9-11).