IDH1 and cholangiocarcinoma: Numerous genomic alterations associated with CCA, including but not limited to fibroblast growth factor receptor 2 (FGFR2), isocitrate dehydrogenase 1 and 2 (IDH1/2), ERBB2 or Catenin Beta 1 (CTNNB1), KRAS, NRAS, BRAF, mismatch-repair deficiency, HER2 (ERBB2), ALK, ROS1, or NTRK, PDGFRA, and RET, have been identified [11,12].