TP63 and head and neck squamous cell carcinoma: The functional link between p63 and TGF-β and other signaling pathways is exemplified by studies showing that the downregulation of p63 is required for TGF-β-induced metastasis in SCC (100), and that the loss of p63 during HNSCC development drives tumor metastasis via mitogen-activated protein kinase signaling (101).