NOTCH1 and head and neck squamous cell carcinoma: The main genetic mutations in HNSCC are on tumor protein p53 – TP53 (71%), fat atypical cadherin - FAT1 (23%), cyclin dependent kinase inhibitor 2A - CDKN2A (22%), Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha - PIK3CA (18%), Notch receptor 1 - NOTCH1 (17%) and HRAS (6%), followed by rare mutations that require further evaluation (61).