Vivian et al. analyzed the GWAS data from 151 HNSCC cases and determined the PI3K was the most frequently mutated (30.5%), and in HPV-associated tumors, only PIK3R1 (453_454insN), PIK3CA (E542K), and PIK3CA (H1047L) were identified 56. Here, PIK3CA is linked to head and neck squamous cell carcinoma.