TGFB1 and neoplasm: Transforming growth factor-β (TGF-β) signaling stands at the nexus of tumor-suppressive and tumor-promoting pathways: in early lesions, it blocks proliferation, whereas in advanced cancers, it drives epithelial-to-mesenchymal transition (EMT), migration, and metastasis through a Smad-dependent transcriptional program [134,135].