Purity ~90% (SDS-PAGE). 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. Source: Recombinant protein corresponding to aa24-134 from human C-C Motif Chemokine 21, fused to GST-Tag at N-terminal, expressed in E. coli. Molecular Weight: ~39.3kD AA