Transforming growth factor-beta 1 (TGF-β1), a cytokine and signaling molecule that plays a crucial role in various cellular processes, including cell growth and differentiation, activates EMT in HNSCC via the so-called SMA and MAD-related protein-dependent pathway (the SMAD-dependent pathway) [94,95,96]. The gene discussed is TGFB1; the disease is head and neck squamous cell carcinoma.