CDKN2A and head and neck squamous cell carcinoma: Of the two major isoforms produced by TP63 (TAp63 and ΔNp63), ΔNp63 plays a major role in HNSCC pathogenesis, regulating key pathways, including cell survival and renewal, senescence suppression (by suppressing p16/INK4A) and growth factor signalling24–26.