The phosphatidylinositide 3-kinase (PI3K) pathway is activated in about half of head and neck squamous cell carcinomas (SCC) by a number of mechanisms, including mutation or amplification of the gene encoding p110α catalytic subunit of phosphoinositide 3-kinase (PIK3CA)[1-4]. This evidence concerns the gene PIK3CA and head and neck squamous cell carcinoma.