Nbs1 controls macrophage functions. (A) ROS induce DSBs, which trigger DDR involving checkpoint kinases ATM, ATR, CHK1, CHK2, and other checkproteins such as p53, CDC25, and BRCA1. A complex of NBS1, MRE11, and RAD50 facilitates DDR. (B) A deficit of NBS1 impairs DDR, resulting in accumulation of DSBs and subsequent deficit of macrophage proliferation, accelerated macrophage senescence, and excessive secretion of inflammatory cytokines.