STAT3 and cancer: The up-regulation of the pro-apoptotic proteins Bax, PARP, AIF, caspase-3, -8, -9 and down-regulation of anti-apoptotic protein Bcl-2 were involved in the Xn-induced cancer cells apoptosis, while the reduced Notch1, mTOR, STAT3, etc. mediated the inhibitive effect of Xn on cancer cells proliferation.