TOPBP1 and breast neoplasm: In this study, we report that the CK2–HTATSF1–TOPBP1 axis is overactivated in a number of tumors, with concomitant amplification and upregulation of CSNK2A1, HTATSF1, and TOPBP1. pS748, a CK2-driven HTATSF1 phosphorylation site, is also significantly elevated and correlates with breast tumor progression.