C1GALT1 and esophageal squamous cell carcinoma: It has been documented that the elevated expression of C1GALT1 contributes to the increased O-glycosylation of Mucin-1 (MUC1) in patients with esophageal squamous cell carcinoma [38] and enhances the invasive and metastatic phenotype by modifying O-glycans on integrin β1 in hepatocellular carcinoma [39].