The transforming growth factor-β (TGF-β) signaling pathway is a highly conserved and complex pathway which has been found to be involved in several hallmarks of cancer, such as resisting cell death, evading growth suppressors, inducing angiogenesis, and activating invasion and metastasis (Figure 1) [17,18,19,20,21,22,23,24]. The gene discussed is TGFB1; the disease is cancer.