FRS2 and infantile convulsions and choreoathetosis: As shown in Fig. 3A,B, a high expression of phospho-FGFR2 and phospho-FRS2α protein was found in the iCCA cases with FGFR2 GAs by IHC and Western blotting analyses, confirming constitutive activation of FGFR2 signalling in this subgroup of patients.