CCR5 and cancer: Since HSPC-like cells are found in the cancer host in the periphery and intratumorally (online supplemental figure 5A), express CCR1 and CCR5 (online supplemental figure 5B), and can be transfected by 4PD (figure 1), we evaluated whether CCR1 and CCR5 blockade can affect the differentiation of HSPC-like cells into MDSCs.