SMAD4 and infantile convulsions and choreoathetosis: Notably, the prevalence of specific mutations differs by etiology and anatomic subtype: IDH1/2 mutations and FGFR2 fusions are enriched in iCCA tumors from Western patients, whereas TP53, and KRAS, along with associated pathways like SMAD4, are more prevalent in fluke-associated and perihilar tumors [15].