GRO (growth-regulated oncogene)-beta or CXCL2 is a member of the CXC family, which plays an integral role in recruitment and activation of neutrophils and basophils in response to tissue injury and microbial infection. GRO-beta and GRO-gamma are closely related to GRO-alpha and share 90% and 86% amino acid sequence homology, respectively, with GRO-alpha. Receptor-binding studies have demonstrated that GRO-alpha, -beta, and -gamma signal mainly through G protein-coupled receptors CXCR1 and CXCR2 (Ahuja and Murphy). GRO-beta is expressed in epithelial cells, monocytes, fibroblasts, and melanocytes and is further induced during inflammatory, epithelialization, and angiogenic processes, for example during the wound healing process of human burn wounds (Zaja-Milatovic and Richmond). GRO-beta also stimulates mitogenesis in certain human melanoma cells (Unemori et al.).