FRS2 and cancer: Upon activation by fibroblast growth factor ligands (FGF1–23), FGFRs phosphorylate their intracellular substrates (e.g., FGFR substrate 2 (FRS2), phospholipase Cγ (PCγ)) (14) and trigger signal transduction pathways that have key roles in mediating cell proliferation, differentiation, migration, and apoptosis as well as in the pathophysiology of a wide spectrum of diseases including cancers (15).