With the exception of tumor 2, all tumor samples showed characteristic mutations of HNSCC including amplification of 3q26.2 (TP63, SOX2, PIK3CA) (1), 5q14.3 (APC) (13, 29, 30), 8q24.3 (PTK2) (25), 8q22.3 (LRP12) (27) as well as loss and/or LOH of 9p21.3 (CDKN2A) (1, 31). This evidence concerns the gene PIK3CA and head and neck squamous cell carcinoma.