AREG and head and neck squamous cell carcinoma: In a previous report, we demonstrated that, like the production of the EGFR ligand amphiregulin in K-RAS mutated (K-RASmut) tumor cells, [2, 9] stimulated amphiregulin secretion is also obvious in head and neck squamous (HNSCC) tumor cells overexpressing K-RAS wild-type (K-RASwt).