KRAS and cholangiocarcinoma: Next-generation sequencing technology has enabled comprehensive mutational and transcriptome profiling of CCA and five identified core driver mutations (TP53, KRAS, SMAD4, ARID1A, and BAP1) and five molecular modules (kinase-RAS, TGFβ-SWI/SNF-MYC, TP53, RB-cell cycle, and epigenetic regulators) [24,25].