CDKN2A and neoplasm: We also identified deletions in regions of commonly described transcription regulators and tumour suppressor genes in HNSCCs [10, 45]: 5q35.2 (NSD1), 20p11 (NKX2-2), 8p22.2 (CSMD1), 9q34.3 (NOTCH1); together with loss of 9p21.3 containing the CDKN2A gene which was found almost exclusively in HPV negative tumours (deletion in 1 out of 15 HPV positive cases) (S4 Fig).