The most frequently mutated genes in this Norwegian cohort of HNSCC were TP53 (n=45, 43.3%), FAT1 (n=23, 22.1%), FLG (n=20, 19.3%), CDKN2A (n=10, 9.6%), and FGFR3 (n=7, 6.7%) (Figure 2). This evidence concerns the gene FLG and head and neck squamous cell carcinoma.