Human GRO-β is a member of the C-X-C family of chemokines and promotes neutrophil and basophil chemotaxis and degranulation. GRO-β like GRO-α specifically inhibits growth factor-stimulated proliferation of capillary endothelial cells in a dose-dependent manner. Recombinant human GRO-β is a 7.9 kDa protein containing 73 amino acid residues.