Not applicable. This is not a chemical compound but likely a cell line or biological reagent used in research, possibly a CHO (Chinese Hamster Ovary) cell line engineered to express the human CXCR2 receptor. Such cell lines are commonly used in drug discovery and development for studying receptor-ligand interactions, screening potential drug candidates, and evaluating the efficacy and specificity of compounds targeting the CXCR2 receptor, which is involved in inflammatory responses and immune cell signaling.