ARID2 and cholangiocarcinoma: The authors identified TP53, AXIN1, RB1, PTEN, ARID2, and BRD7 as significantly mutated genes, together with eight other recurrent genes reported in HCC and CC (TERT promoter, KMT2D, KEAP1, ARID1A, PTEN, RPS6KA3, CTNNB1, IDH1, PBRM1) as potential drivers in cHCC-CC (Table 1).