MEK/ERK and PI3K/AKT pathways are deregulated in the majority of HNSCCs and HNSCC cell lines (Amornphimoltham et al, 2005; Massarelli et al, 2005; Pedrero et al, 2005; Van Baal et al, 2006; Yu et al, 2007a, 2007b; Bussink et al, 2008). This evidence concerns the gene PIK3CA and head and neck squamous cell carcinoma.