Schematic representation of a proposed model depicting functional influences of genetic variations in BMPR1B 3′UTR on endometriosis development.

Mature miRNAs including miR-125b are produced by several processing steps where the microprocessor complex (Drosha/DGCR8), exportin 5 and Dicer/TRBP/PACT complex have been known to involve in. The resulting miR-125b forms a RISC complex with Ago and silences BMPR1B gene by binding to the complementary sequence in BMPR1B 3′UTR. Impaired recognition due to genetic variations in the mir-125b seed region reduces suppressive effect of mir-125b, resulting in up-regulation of BMPR1B. The CA125 level, a biomarker for endometriosis and ovarian cancer, was found reversely correlated with BMPR1B in endometrium cells. Elevated BMPR1B levels in endometrium cells have been proven to reduce cell proliferation and migration activity via down-regulation of IL-1β, indicating a lower risk to develop endometriosis.