Accordingly, concomitant molecular assessment of phosphorylated FGFR2 and phosphorylated FRS2α protein expression in tumor tissue by routine methodologies such as IHC analysis could represent a more reliable biomarker, rather than the only genetic testing of FGFR status, to select iCCA patients candidate to FGFR targeted therapies. The gene discussed is FRS2; the disease is infantile convulsions and choreoathetosis.