CSF1 and neoplasm: Studies have shown that some neutralizing antibodies or inhibitors targeting chemokine systems (CXCR4, CXCR2, and CCL2) and tumor-derived factors (CSF1, GM-CSF, and IL-6) can inhibit the expansion or recruitment of MDSC (Bayne et al., 2012; Sumida et al., 2012; Highfill et al., 2014).