CDKN2A and skin squamous cell carcinoma: M.B. Lobl et al. performed targeted next-generation sequencing of matched, localized, and metastatic primary high-risk cSCC and found that the most frequently mutated genes in localized and metastatic cSCC, respectively, were TP53 (70% vs. 70%), CDKN2A (20% vs. 40%), KDR (4% vs. 30%), SMAD4 (30% vs. 20%), NOTCH1 (20% vs. 10%), PTEN (10% vs. 20%), and KIT (10% vs. 20%).