CXCL1 and triple-negative breast carcinoma: Conditioned medium collected from hAdSCs elicits doxorubicin resistance and enhances the expression of ABCG2, which is a transporter responsible for the efflux of doxorubicin. CXCL1 secreted by hAdSCs downregulates miR-106a expression in triple-negative breast cancer and thus upregulates the ABCG2 and doxorubicin resistance.