H2AZ1 and cholangiocarcinoma: To evaluate the methylation status of H2AZ1 and H2AZ2 promoters in CC, we used the DiseaseMeth2.0 database finding a significant reduction in H2AZ2 promoter methylation in CC compared with normal tissue (Student’s t-test; H2AZ2 P-value=3.538e-07; Figure 3E right), suggesting that H2AZ2 hypomethylation could be associated with overexpression of the H2A.Z.2 isoform.