CDKN2A and squamous cell carcinoma: From the study with squamous cell carcinoma, notable results include a high rate of copy number alterations in SOX2, PDGFRA, KIT, EGFR, FGFR1, WHSC1L1, CCND1, and CDKN2A; a total of 228 non-silent and 360 exonic mutations; the detection of significantly mutated genes, including TP53, CDKN2A, PTEN, PIK3CA, KEAP1, MLL2, HLA-A, NFE2L2, NOTCH1, and RB1; overexpression of SOX2 and TP63; inactivation of CDKN2A in 72% of cases; and EGFR amplifications in 7% of samples [52].