Simultaneously, in the Cancer Genome Atlas (TCGA) database, a subgroup of head and neck squamous cell carcinoma (HNSC, samples = 508) patients with favorable clinical outcomes showed infrequent copy number alterations that were correlated with activating mutations of HRAS, RAF, RAC1, and ERK1/2 (Supplemental Figure 2). Here, MAPK3 is linked to head and neck squamous cell carcinoma.