MED12 and leiomyoma: In this context, it is noteworthy to mention that the mediator complex subunit 12 (MED12) gene, which has been previously demonstrated to regulate β-catenin/WNT signaling, has mutations in exon 2 in nearly 70% of uterine leiomyomas.[83] The role(s) for such signaling pathways in the endometrium of women with fibroids has to date not been determined.