Analysis of TCGA Pan-Cancer Atlas dataset revealed a 9-fold and 4-fold enrichment of RAC1 mutations in melanoma (6.53%, n = 29/444) and HNSCC (2.94%, n = 13/510), when compared to the average pan-cancer RAC1 mutation rate of 0.728% (76/10433 cases). The gene discussed is RAC1; the disease is head and neck squamous cell carcinoma.