The number of MDSCs can be reduced by blocking the chemokine or cytokine receptors (e.g., CCR5, CSF-1R, CXCR1, and CXCR2) targeting MDSCs, which prevented myeloid marrow cells from trafficking into peripheral lymphoid organs or the tumor microenvironment (263–266). The gene discussed is CXCR1; the disease is neoplasm.