ATR and Hyperglycemia: We investigated whether human breast cancer cells, when cultured under hyperglycemia, are more vulnerable to DNA repair inhibitors, assessing a panel of cancer drugs that included the checkpoint kinase inhibitor AZD7762, the ATR (ataxia telangiectasia and Rad3 related) inhibitor berzosertib, the topoisomerase II inhibitor etoposide, and the PARP inhibitor olaparib.