TLR4 and endometriosis: To date, more than 13 members of TLRs family have been identified, the most studied one being Toll-like receptor 4 (TLR4) and Toll-like receptor 2 (TLR2) [134,135,136], although the presence of TLR 1 to TLR 6 (TLR1, 2, 3, 4, 5, and 6), was reported in epithelia of different regions of endocervix, endometrium, and uterine tubes in patients with endometriosis [135,137,138].