It has not been clear how the cytoplasmic protein p120 catenin regulates cell motility. Overexpression of p120 catenin in fibroblasts modulates the actin cytoskeleton and promotes cell motility, yet binding to the cytoplasmic domain of coexpresssed cadherins, cell surface adhesion proteins, inhibits this effect. Noren et al. now report that, when in the cytoplasm, p120 catenin binds to Vav2, an exchange factor that activates Cdc42 and Rac1. These small GTP-binding proteins alter the actin cytoskeleton and promote cell motility. However, the presence of cadherins can cause a decrease in the availability of cytoplasmic p120 and thus inhibit cell migration and promote cell-cell adhesion. The authors suggest that the distribution of p120 catenin between the cadherin-bound state and the cytoplasmic pool is important in determining cell motility.