DNA double strand fission, like its atomic counterpart, is useful when controlled but
potentially lethal when not. On the useful side, the programmed DNA double strand break
(DSB) is an essential step in the important cellular processes of V (D) J and class-switch
recombination during immune system development, and homologous recombination during
meiosis and mitosis. In contrast, the unprogrammed DSB is the single most potentially lethal
type of lesion a cell can sustain—a single DSB may be lethal. While the high energy …