FRS2 and neoplasm: Among these patients, 10 out 17 cases expressed FGF10 ligand, FGFR2 and phosphorylated FGFR2 in the tumor tissue, but not phosphorylated FRS2α protein, the main downstream effector of activated FGFR2 signalling (Fig. 5A,B); the other seven cases expressed wild-type FGFR2 protein, but were negative for FGF10 ligand, phosphorylated FGFR2 and phosphorylated FRS2α protein expression (Fig. 5A,B).