A recent study has shown that apigenin has anti-tumor effects on prostate cancer stem cells isolated from PC3 and LNCaP cell lines, through the up-regulation of p21, p27 (cyclin-dependent kinase inhibitor), Bax proteins, and caspases-3 and-8 along with the down-regulation of NF-κB, poly (ADP-ribose) polymerases (PARP), and phosphor-p38 (p-p38). This evidence concerns the gene CDKN1B and neoplasm.