Based on previous findings showing that the interaction of the chemokine receptor CXCR2 expression on MDSC and cancer cell-derived chemokines play important roles in tumor progression [21], we confirmed the expression of chemokine (CXC motif) ligand 2 (CXCL2) in Hela and MDA-MB-231 cells (Figure 5B) as well as CXCR2 expression in MDSC (Figure 5C). Here, CXCR2 is linked to cancer.