 Conditional (CD21-cre-mediated) deletion of the XRCC4 NHEJ gene in p53-deficient peripheral mouse B cells resulted in surface Ig-negative B-cell lymphomas, and these lymphomas often had a "reciprocal chromosomal translocation" fusing IgH to Myc (and also had "large chromosomal deletions or translocations" involving IgK or IgL, with IgL "fusing" to oncogenes or to IgH).XRCC4- and p53-deficient pro-B lymphomas "routinely activate c-myc by gene amplification"; and furthermore, XRCC4- and p53-deficient peripheral B-cell lymphomas "routinely ectopically activate" a single copy of c-myc.Indeed, in view of the observation by some that “DNA repair enzymes are correctives for DNA damage induced by carcinogens and anticancer drugs”, it should not be surprising that “SNPs in DNA repair genes may play an important part” in cancer susceptibility.