CCL20 and breast cancer: Furthermore, utilizing qRT-PCR (Supplementary Fig. S14b, c), in vitro LDA (Supplementary Fig. S14d, e), and AIG assay (Supplementary Fig. S14f), we also confirmed that CXCL2 neutralizing antibody inhibited breast cancer cell stemness promoted by CCL20-modulated PMN-MDSCs, suggesting CCL20-modulated PMN-MDSCs promoted the cancer cell stemness by secreting amounts of CXCL2.