Importantly, the limiting dilution BM transplantation studies showed that all recipients of even 1x105 BM from MSH2-/- mice developed thymic lymphomas (Fig 2C), and the frequency of HSCs in mouse BM is about 0.01% of total nucleated cells[37,41], suggesting that perhaps every HSC in MSH2-/- mice has the lymphomagenetic potential. This evidence concerns the gene MSH2 and thymus lymphoma.