PPFIA1 and head and neck squamous cell carcinoma: Taking into account the five most SCN-altered genes in HNSCC, deletion was observed in CDKN2A, CDKN2B, and amplification in PPFIA1, FADD and ANO1. These results concur with recent studies [31] and also with other known cancer driver amplifications, such as SOX2, PIK3CA, EGFR and CCDN1.