MED12 and lymphangioma: We demonstrate that increased ROS is evident in the myometrium of uteri with high number of LM tumors, that treatment of myometrial cells in vitro with ROS inducers causes increased 8-OHdG, that insertion of oxidized guanines at c.130-131of MED12 using CRISPR/Cas9 technology promotes misrepair and mutations, and that both acute and chronic treatments of myometrial cells promote mutations of MED12 at sites similar to hot spot mutations found in LM tumors.