DNA double-strand breaks (DSBs) are the most serious form of DNA damage.In human cells,non-homologous end joining (NHEJ) is the major pathway for the repair of DSBs.Different types of DSBs result in different subsets of NHEJ repair strategies.These variations in NHEJ repair strategies depend on numerous elements,such as the flexible recruitment of NHEJ-related proteins,the complexity of the DSB ends,and the spatial-and temporal-ordered formation of the multiprotein complex.On the one hand,current studies of DNA DSBs repair focus on the repair pathway choices between homologous recombination and classic or alteative NHEJ.On the other hand,increasing researches have also deepened the significance and dug into the cross-links between the NHEJ pathway and the area of genome organization and aging.Although remarkable progress has been made in elucidating the underlying principles during the past decades,the detailed mechanism of action in response to different types of DSBs remains largely unknown and needs further evaluation in the future study.