MUC1 and cholangiocarcinoma: In summary, our data show the following: (1) GATA6 promotes EMT by upregulating MUC1 in CCA; (2) GATA6 upregulates MUC1 through binding to both the 1584 and 1456 GATA motifs in the promoter and enhancing its transcriptional activity; and (3) MUC1 promotes EMT by binding to β-catenin and increasing its nuclear expression in CCA.