CASP8 and neoplasm: Considering copy number alterations and truncating, missense and in-frame mutations, 23% of tumours of the oral cavity harboured mutations in FAT1 alone, 5.8% in CASP8 alone and 9.3% in both FAT1 and CASP8, compared with 22%, 2.8% and 1.9%, respectively, in tumours of other areas of the head and neck.