In this study, a novel pathway of resistin-promoted breast cancer was highlighted with the effect of resistin indirectly promoting breast cancer cell malignancy via CXCL5 secretion in the tumor microenvironment, leading to the downstream ERK activation and epithelial-to-mesenchymal transition towards mesenchymal phenotypes in breast cancer cells. The gene discussed is CXCL5; the disease is neoplasm.