TGFB1 and cancer: This can be interpreted to mean that in vivo cancer cells utilize autocrine TGFβ1 to protect themselves against the actions of stromal cell-derived paracrine TGFβ and suggest the possibility that a finely tuned balance of the antagonistic actions of autocrine and exogenous TGFβ(1) also controls the generation of EMT phenotypes with enhanced plasticity and stem cell potential.