Brassinin is a phytoalexin isolated from cruciferous vegetables that exhibits anticancer, chemopreventive, antiproliferative and antifungal activities. In lung cancer cells, brassinin inhibits constitutive and IL-6-inducible STAT3 signaling through modulation of PIAS-3 and SOCS-3. It appears that brassinin induces apoptosis in PC-3 prostate cancer cells via the suppression of PI3K/Akt/mTOR/S6K1 signaling.