Cryptotanshinone is one of the major tanshinones isolated from the roots of the plant Salvia miltiorrhiza Bunge (Danshen). Danshen has been widely used in traditional Chinese medicine for treatment of a variety of diseases, including coronary artery disease, acute ischemic stroke, hyperlipidemia, chronic renal failure, chronic hepatitis, and Alzheimer's disease, showing no serious adverse effects. Recent studies have shown that cryptotanshinone not only possesses the potential for treatment and prevention of the above-mentioned diseases, but also is a potent anticancer agent. In vitro studies have demonstrated that cryptotanshinone inhibits cell proliferation in a variety of cancer cell lines, including rhabdomyosarcoma, melanoma, cervical, colon, breast and prostate cancer cells. It has been described that cryptotanshinone induced a G1/G0 cell cycle arrest in rhabdomyosarcoma (Rh30) and prostate cancer (DU145) cells by downregulating expression of cyclin D1 and phosphorylation of retinoblastoma protein (Rb), but induced a G2/ M cell cycle arrest in melanoma (B16) cells via upregulating expression of Cdc25c, cyclin A1 and cyclin B1. Cryptotanshinone inhibiting expression of Aurora A kinase led to significant suppression of prostate cancer cells in vitro and in mice. Cryptotanshinone also induces cell death in cancer cells.