TGFB1 and cancer: While acting as a tumor suppressor by stimulating cell cycle arrest and cellular senescence, as well as evoking apoptosis and autophagy in the early stages of tumor progression, TGF-β is redirected away from thwarting cell survival and is found instead to switch to a promoter of tumor progression in the late stages, especially when cancer cells acquire resistance to its cytostatic and apoptotic effects.