CDKN2A and head and neck squamous cell carcinoma: Mutations in FAT1, CDKN2A, NOTCH1 and TGFBR2 have been reported to be frequent in SCCHN; all mutations of these loci in our cohort were found to be truncating (either as nonsense or frameshift) and often appeared as a double hit, suggestive of inactivation of both alleles (i.e. YHIM-06 and -07 showed nonsense and frameshift mutations for FAT1 and NOTCH1, respectively).