Since XRCC4/p53 double knockout mice developed pro-B-cell lymphomas with IgH-c-myc chromosomal translocations, it is interesting to see whether XLF/PAXX/p53-deficient mice also develop lymphoma that is reminiscent to XRCC4/p53 double knockout mice (60). The gene discussed is NHEJ1; the disease is B-cell non-Hodgkin lymphoma.