C1GALT1 and breast cancer: At the molecular level, C1GALT1 expression regulates O‐glycosylation of receptors and pathways such as MET in hepatocellular carcinoma, FGFR2 in colorectal cancer, Mucin 1 and CD44 in breast cancer, EGFR and PD‐1 in head and neck squamous cell carcinoma, and EPHA2 in gastric cancer [21, 22, 23, 24], significantly influencing cancer behaviors.