To investigate the effects of the rhAPE1/Ref-1 and ASA combination treatment on tumor apoptosis in TNBC in vivo, the TUNEL assay for detecting DNA fragmentation, which is a hallmark of apoptosis, was performed on tumor tissues from TNBC xenograft mice treated with TNBC control, rhAPE1/Ref-1, ASA, ASA + rhAPE1/Ref-1, or PTX. The gene discussed is APEX1; the disease is neoplasm.