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. The gene discussed is CDH1; the disease is cancer.