MDC1 and neoplasm: More importantly, NFBD1 knockdown can delay IR-induced DNA damage repair in the early phase of the DDR, also this enhanced radiosensitivity was accompanied by an increased induction of apoptosis in a later phase, inhibited growth, xenografts models in nude mice showed that silencing NFBD1 significantly enhanced the antitumor activity of IR, leading to tumor growth inhibition of the combination therapy.