Of the various types of DNA damage that can occur within the mammalian cell, the DNA
double strand break (DSB) is perhaps the most dangerous. DSBs are typically induced by
intrinsic sources such as the by products of cellular metabolism or by extrinsic sources such
as X-rays or γ-rays and chemotherapeutic drugs. It is becoming increasing clear that an
inability to respond properly to DSBs will lead to genomic instability and promote
carcinogenesis. The mammalian cell, therefore, has in place several mechanisms that can …