FGF19 and head and neck squamous cell carcinoma: Despite the expression of several fibroblast growth factor (FGF) receptors in HNSCC, surprisingly little investigation has focused on secretion of the FGF gene products FGF-3, FGF-4, and FGF-19 located within the 11q13 amplified region found in nearly a third of HNSCC patient samples [91,92].