When 500 ng/ml CXCL1 antibody or 400 nM CXCR2 inhibitor SB225002 was added into CAF medium, SOD1 was significantly upregulated in tumor cells (Figures 4c–e), suggesting CAF-secreted CXCL1 inhibited the expression of SOD1. This evidence concerns the gene CXCR2 and neoplasm.