Inhibits hemopoiesis and stimulates chemotaxis. Chemotactic in vitro for thymocytes and activated T-cells, but not for B-cells, macrophages, or neutrophils. Shows preferential activity towards naive T-cells. May play a role in mediating homing of lymphocytes to secondary lymphoid organs. Binds to atypical chemokine receptor ACKR4 and mediates the recruitment of beta-arrestin (ARRB1/2) to ACKR4 (By similarity). Monomer. Binds to CCR7. Interacts with PDPN; relocalizes PDPN to the basolateral membrane. Interacts with TNFAIP6 (via Link domain). Belongs to the intercrine beta (chemokine CC) family.