FGFR2 and head and neck cancer: In HNC, MAPK pathway mutations occur in ~18% of patient tumors.73 These mutations predominantly occur in BRAF, HRAS, KRAS, and ERK.77 The activators and regulators of the MAPK pathway (NF1, fibroblast growth factor receptor 2 (FGFR2), FGFR3, and ErbB3) have also been found.78 Moreover, almost half of the MAPK pathway mutations in head and neck cancer are activating or drivers of tumorigenesis.70 When growth factors bind to RAS, a signal cascade is activated.