CHEK2 and breast cancer: Given that some CHEK2 germline variants may confer a higherrisk of BC susceptibility than the CHEK2 p.Ile157Thr allele, our findings are consistent with the hypotheses that either, in a subset of BCs, the CHEK2 p.Ile157Thr variant confers BC susceptibility through a biological mechanism distinct from that of high-risk CHEK2 mutations or this variant may constitute an incidental finding (ie, sporadic BCs developing in the context of a CHEK2 p.Ile157Thr germline variant).