IDH1 and cholangiocarcinoma: So far, two mutant IDH inhibitors, enasidenib and ivosidenib have been approved by the US Food and Drug Administration (FDA) - for IDH-mutant relapsed or refractory acute myeloid leukaemia (AML) and continue to be studied in trials in hematologic malignancies, as well as in glioma, cholangiocarcinoma, and chondrosarcoma [4-7].