Mutations of mediator subcomplex 12 (MED12) and of high mobility group protein AT-hook 2 (HMGA2) are driver mutations in uterine leiomyomas (UL) that have not been observed to coexist in one tumor and even rarely coexist in different UL tumors of one patient. This evidence concerns the gene HMGA2 and uterine corpus leiomyoma.