Chemokine (C-X-C motif) ligand 1 (CXCL1), also known as KC or N51, is a small cytokine belonging to the CXC chemokine family. It was originally identified in fibroblasts as a PDGF-induced immediate early gene that encodes a secretory protein of approximately 8 kDa.
CXCL1 is expressed by macrophages, neutrophils and epithelial cells, and has neutrophil chemoattractant activity. CXCL1 plays a role in spinal cord development by inhibiting the migration of oligodendrocyte precursors and is involved in the processes of angiogenesis, inflammation, wound healing, and tumorigenesis. CXCL1 is induced by inflammatory cytokines such as IL-1 and TNF, and IL-17A enhances expression of CXCL1 by prolonging the half-life of its constitutively unstable mRNA. An initial study in mice showed evidence that CXCL1 decreased the severity of multiple sclerosis and may offer a neuro-protective function.