Here, using data from TCGA-HNSCC (n = 510 patients, Firehose cohort, USA), we noted RAC1 gene copy gain in ~37% (188/510) of cases, RAC1 amplification in 2% (10/510) of cases, and RAC1 mutation in 3% (15/510) of cases, totaling ~42% of HNSCC cases. Here, RAC1 is linked to head and neck squamous cell carcinoma.