HRAS and head and neck squamous cell carcinoma: Recently, next-generation sequencing (NGS) studies have revealed that the genetic alterations in HNSCC are mainly in a group of molecular pathways and/or biological processes including p53 pathways (TP53), mitogenic pathways (RAS/PI3K/mTOR pathway, PIK3CA, HRAS), cell cycle (CDKN2A), Notch pathways (NOTCH1, NOTCH2, NOTCH3), and cell communication and death (FAT1, CASP8) [8] (Reviewed in [9]).