In uterine leiomyoma, ISL induces cell cycle arrest in the subG1 and G2/M phases by increasing p21Cip1/Waf and reducing Bcl-2, cdk 2/4, and E2F, thereby suppressing the proliferation of primary uterine leiomyoma cells. Here, CDKN1A is linked to uterine corpus leiomyoma.