Comprehensive examination of genomic alterations in HNSCC was reported by investigators from The Cancer Genome Atlas (TCGA) Research Network showed that many HNSCC have alterations in genes for growth factor receptors (EGFR, FGFR, IGFR, MET, ERBB2, and DDR2), signaling molecules (PIK3CA and HRAS), and regulation of genomic integrity and the cell cycle (TP53, CCND1). This evidence concerns the gene PIK3CA and head and neck squamous cell carcinoma.