WNK2 and cholangiocarcinoma: Genetic and microarray data analysis revealed that genes of the Mitogen-activated protein kinase (MAPK) pathway are enriched in CCA as similarly seen in hepatocellular carcinoma (HCC) [7] and the Mitogen-Activated Protein Kinase (MAPK) pathway was demonstrated to be activated in CCA tissue compared to non-tumorous tissue [8].