CXCR4 and neoplasm: Consistent with changes in arginase expression, neutrophils treated with the supernatant harvested from H1299 cells mixed with CAFs produced significantly more N2-type neutrophils (Fas and CCL3 downregulation; CCL2 and CXCR4 upregulation) and tumor-promoting cytokines (MMP-9) than did untreated neutrophils or those treated with the supernatant from H1299 or CAF mRNA (Supplementary Figures 3A–E).