MUC1 and cancer: Overexpression of MUC1 has been shown to inhibit E-cadherin-mediated cell–cell interactions and to increase the ability of the cancer cells to detach from adjacent cells at primary tumour sites and to promote tumourigenesis.15,37 Interaction of cancer-associated MUC1 with circulating galectin-3, a galactoside-binding protein whose concentration is markedly increased up to 30-fold in the bloodstream of cancer patients,21 via expression of the oncofetal TF antigen on MUC1,38 induces MUC1 cell surface polarization and exposure of the cell surface adhesion molecules.