Catenin delta-1 (p120 catenin) has an amino-terminal coiled-coil domain followed by a regulatory domain containing multiple phosphorylation sites and a central Armadillo repeat domain of ten linked 42-amino acid repeats. The carboxy-terminal tail has no known function (1). Catenin delta-1 fulfills critical roles in the regulation of cell-cell adhesion as it regulates E-cadherin turnover at the cell surface to determine the level of E-cadherin available for cell-cell adhesion (2). Catenin delta-1 has both positive and negative effects on cadherin-mediated adhesion (3). Actin dynamics are also regulated by catenin delta-1, which modulates RhoA, Rac, and cdc42 proteins (1). Analogous to beta-catenin, catenin delta-1 translocates to the nucleus, although its role at this location is unclear. Many studies show that catenin delta-1 is expressed irregularly or is absent in various types of tumor cells, suggesting that catenin delta-1 may function as a tumor suppressor (4).