MAGI1 and cancer: Using MCF7 cancer cells, immortalized hMEC (human mammary epithelial cells), and polarized canine MDCK cells, we further confirmed by immunofluorescence that MAGI1 localized near the plasma membrane, overlapping with junction components such as E-cadherin (AJ), ZO1, and Claudin3 (TJ), suggesting that MAGI1 is a TJ and/or AJ resident protein (Fig. 3A, arrows and data not shown).