In summary, we suggest that DNA damage-inducing therapies such as IR and chemotherapy drugs not only destroy cancer cells by damaging their DNA, but also trigger an ATM/ATR-KIFC1 phosphorylation-centrosome clustering pathway to selectively maintain the survival of the centrosome-amplified cancer cells, which in turn leads to CIN, metastasis, and tumor recurrence. Here, ATR is linked to cancer.