IDH2 and intrahepatic cholangiocarcinoma: Focusing on the genomic findings from all ICC studies discussed above, recurrent mutations of ICC are enriched in tumor suppressor genes, i.e., ARID1A, ARID1B, BAP1, PBRM1, TP53, STK11, and PTEN, and oncogenes, i.e., IDH1, IDH2, KRAS, BRAF, and PIK3CA. The frequencies of these recurrent mutations in ICC across multiple studies are summarized in Figure 1.