While studying adherens junctions and one of their components, N-cadherin, in primary astrocytes, Peglion et al. noted that they flowed continuously from the front to the back of leader cells during collective cell migration. Furthermore, N-cadherin was trafficked to the front edge of leading cells, where it was incorporated into new junctions. How is this polarized recycling of N-cadherin regulated? p120 catenin, which interacts with N-cadherin and is required for its stability at the leading edge of migrating cells, was phosphorylated at Thr310 by GSK3β at the rear of cells but not at the front. This phosphorylation event reduced N-cadherin–p120-catenin interactions, which explains how N-cadherin is free for recycling at the cell rear but incorporated into adherens junctions at the cell front.