NOTCH1 and cholangiocarcinoma: Similar epigenetic phenomena were described in human cholangiocarcinoma (CCA), in which Enhancer of zeste homolog 2 (EZH2)-mediated histone 3 trimethylation of lysine 27 (H3K27me3) in the same promoter lowered miR-34a levels and promoted Notch1 signalling [80].