Clearing the Path for Germ Cells

The chemokine SDF-1a and its receptor CXCR4b guide germ cell migration in zebrafish by activating downstream signaling events. now report that a second SDF-1a receptor, CXCR7, is also required for guided migration but does not function as a signaling receptor, and instead sequesters SDF-1a. These results highlight the importance of ligand clearance during guided cell migration.