CXCR2 and neoplasm: Approximately 70% of the tyrosinase expressing GFP-positive tumor cells expressed CXCR2 in the tumors arising in Braf/Pten/CXCR2WT model and 30% of the tyrosinase expressing GFP + tumor cells in the Braf/Pten/Cxcr2−/− model continued to express CXCR2.