Previous studies showed that C1GALT1 is overexpressed in hepatocellular carcinoma, colorectal cancer, breast cancer, head, and neck squamous cell carcinoma, and gastric cancer [23–28]; and increased C1GALT1 expression correlates with higher histological grade, or advanced tumor stage and poor survivals in the above cancers. This evidence concerns the gene C1GALT1 and breast cancer.