On the other hand, human tumor studies showed that chemokines such as CXCL1 and CXCL8 are produced by tumor cells, macrophages, and neutrophils to recruit further neutrophils, macrophages, and sometimes myeloid-derived suppressor cells (MDSC) where the MDSC would prevent the killing of tumor cells [26]. The gene discussed is CXCL1; the disease is neoplasm.