In fact, for reasons unclear, the majority of RAC1-mutated cases were HPV(−)HNSCC: Five out of the six A159V-mutated HNSCC cases (83.3%; 5/6) and eight of the 10 of the G-box-mutated cases (80%; 8/10) were HPV(−)HNSCC. This evidence concerns the gene RAC1 and head and neck squamous cell carcinoma.