However, MUC1 has long been viewed as a tumour-associated molecule due to its frequent overexpression and aberrant glycosylation in many carcinomas (>90% of breast carcinomas, and frequently in other types of cancer, including ovarian, lung, colon, gastrointestinal and pancreatic carcinomas), where it is associated with metastatic and invasive potential [52,55,113]. Here, MUC1 is linked to cancer.