Recently, plectronthoic acid, a novel compound, demonstrated potent significant anti-tumor activities by inhibiting proliferation, induced G0/G1 phase arrest in prostate cancer (PC3, DU145, and CW22Rv1) cells via upregulation of p21/CIP1 and p27/KIP1, and also suppressed mTOR/S6K signaling pathway [161]. This evidence concerns the gene CDKN1A and prostate cancer.