Furthermore, when crossing ataxia telangiectasia mutated (ATM) deficient mice onto a cblb-deficient background, 50% of ATM−/−cblb+/+ mice died within 6 months of age of spontaneous T cell lymphomas while no death was observed among ATM−/−cblb−/− double knockout mice. The gene discussed is ATM; the disease is T-cell non-Hodgkin lymphoma.