Studies in mice have shown that homozygous deletion of the gene encoding Ku70 results in an increased incidence of spontaneous T cell lymphoma and decreased survival as compared to WT mice (25, 26) and that Ku70 detects cytoplasmic DNA in human Jurkat T lymphocytes and aged primary mouse CD4+ T cells, leading to the activation and proliferation of these cells driving age-related autoimmunity (24). The gene discussed is XRCC6; the disease is T-cell non-Hodgkin lymphoma.