FOXP3 has been shown to exert its growth inhibitory effect on breast and prostate cancer cells by transcriptionally repressing the expression of specific oncogenes (HER2, SKP2, SATB1 and MYC) [2, 3, 14, 15], and inducing the expression of specific tumor suppressor genes (CDKN1A, LATS2) [16, 17]. The gene discussed is CDKN1A; the disease is prostate cancer.