IDH1 and intrahepatic cholangiocarcinoma: Ivosidenib (AG120), a small molecule and selective inhibitor, has been developed targeting the IDH1 mutation and has recently been approved by the FDA for use in advanced-stage and metastatic intrahepatic cholangiocarcinoma (iCCA) (Norsworthy et al., 2019; Zhu and Kwong, 2022).