The role of SPAG5 in cancer hallmarks of TNBC cells was investigated by a colony formation assay; and the effects of SPAG5 on the chemoresistance of doxorubicin and docetaxel was investigated by cytotoxicity assay, caspase 3/7 activity analysis, mitochondrial membrane potential assay, flow cytometry, and fluorescence microscopy. This evidence concerns the gene SPAG5 and cancer.