FGFR2 and biliary tract neoplasm: Of note, theyare found nearly exclusively in intrahepatic, but not in perihilar or extrahepaticCCA, or hepatocellular carcinoma.9,10,12 Fusions that involve othermembers of the FGFR family are rare in biliary tract cancers, with an incidencebelow 0.5%.13 Although there is initial evidence that FGFR2 genetic alterations occur morefrequently in younger patients and are associated with a more indolent disease progression,13 it remains enigmatic whether FGFR2 fusion positive patients represent adistinct prognostic subgroup.