We next assessed the influence on EGFR activity of MUC1 cell surface interaction with galectin-3 at pathological galectin-3 concentrations observed in cancer patients.24, 31 Without the presence of EGF, introduction of galectin-3 had no significant effect on EGFR activation in either MUC1-positive or -negative cells of breast origin (Figures 3a–f). Here, MUC1 is linked to cancer.