SMAD3 and cancer: Overall, the disruption of TGF-β signaling in cancer is attributed to several well-established mechanisms, including mutations in the genes encoding components of the signaling pathway, such as TGFBR1, TGFBR2, SMAD2, SMAD3, and SMAD4, frequently observed in various cancer types, including colon cancer, pancreatic cancer, and glioblastoma [57–59].