It has been reported that ERβ plays an important role in EMS pathogenesis by modulating its target genes (6), including NRF1, SOD2, COX2, and MMP1, and specific ERβ suppression, such as ERβ antagonist (17), has been used for treatment of endometriosis, but with many of limitations and side effects. This evidence concerns the gene PTGS2 and endometriosis.