sentences:  Cellular response is performed by damage sensors, effectors of lesion repair and signal transduction.The central role is carried out by ataxia telangiectasia mutated (ATM) by activating the DSB signaling cascade, phosphorylating downstream substrates such as histone H2AX and NBS1.NBS1 relocates to DSB sites by interaction of FHA/BRCT domains with phosphorylated histone H2AX.