Murine CXCL1, also known as KC, is belonging to the CXC chemokine family. It is encoded by the GRO gene now designated CXCL1. The gene for CXCL1 was initially discovered in mouse fibroblasts by plateletderived growth factor. KC is member of the intercrine alpha (chemokine C-X-C) subfamily of chemokines. It is secreted by human melanoma cells, and also expressed by macrophages, neutrophils and epithelial cells. The functional receptor for CXCL1 has been identified as CXCR2. CXCL1 has chemotactic activity for neutrophils, and plays a role in inflammation and wound healing. Amino acid sequence of murine CXCL1 is approximately 60 % identical to the human CXCL1. KC was found to be involved in monocyte arrest on atherosclerotic endothelium and may also play a pathophysiological role in Alzheimer’s disease.