H2AX and neoplasm: It has been established that the process of senescence is triggered and maintained by activated DDR pathways, including protein kinase ataxia telangiectasia mutated (ATM), histone H2AX, and their downstream mediators p53‐binding protein 1 (53BP1) and checkpoint kinase 2 (CHK2).[35] We therefore investigated whether induction of DDR is involved in citrate‐induced tumor cell senescence.