To test this hypothesis, we first used BMS-345541 (BMS), a specific IKKβ inhibitor [10], to selectively inhibit the IKK-NFκB pathway and found that it could significantly inhibit the repair of IR-induced DSBs in MCF-7 human breast cancer cells and H1299 and H1648 human lung cancer cells. The gene discussed is IKBKB; the disease is breast carcinoma.