IDH2 and cholangiocarcinoma: IDH1 mutations are more commonly observed in chondrosarcomas (13.1%), cholangiocarcinomas (51.0%) and gliomas (71.2%); IDH2 is more commonly affected in angioimmunoblastic T cell lymphoma (25.0%) and sinonasal undifferentiated carcinoma (82.0%); and AML shows a more similar percentage of mutations in the two genes (IDH1 - 13.1%; IDH2 - 18.2%) (Pirozzi and Yan, 2021).