CXCL1 and neoplasm: Consistent with patterns of heavy Ly6Ghi gMDSC infiltration, MOC1 tumors expressed increased transcript levels of CXCR2 and the CXCR2 ligands CXCL1 and CXCL2, with a significant increase in expression between days 10 and 20 of tumor progression (Figure 10D).