To further investigate the clinical relevance of the CK2–HTATSF1–TOPBP1 axis in breast tumorigenesis and chemotherapy, stable shControl and shHTATSF1 MDA-MB-231 breast cancer cells were orthotopically transplanted into the mammary fat pads of 6-week-old immunocompromised female severe combined immunodeficiency (SCID) mice followed by DMSO or cisplatin treatment. This evidence concerns the gene TOPBP1 and breast cancer.