It is highly likely that olNbs1 Q170 residue has an important role in DSB repair from the following 2 findings: (1) olNbs1 Q170 residue corresponds to the Q185 residue of hNBS1, which has been reported to be associated with the increased risk of a variety of cancers (S2 Table); (2) the sequence around Q170 was highly conserved among animal species (Fig 1A). This evidence concerns the gene NBN and cancer.