CDKN2A and skin squamous cell carcinoma: A number of key gene alterations have been shown to be involved in the pathogenesis and development of cSCC, such as tumor suppressors (p53, CDKN2A, p16, KMT2D), cell proliferation/apoptosis/cell signaling (NOTCH, PI3K/AKT, RAS/MAPK, INPP5A, EGFR, CYFIP1, E6, TERTp), immune system regulations (PD‐L1, lectin‐like transcript 1), tissue invasion (E‐cadherin, podoplanin, chemerin, FAK) and epigenetic regulation (KMT2C, ERRα, CpG promoter methylation) [1, 14, 15].