Expressions of several oncogenes, known to be involved in leukomogenesis, were analyzed and were not up-regulated in the thymic lymphomas compared to the Tcf1−/− without lymphomas (Tal1, Tal2, Lyl1, Lmo1, Lmo2, SilTal, p53; unpublished data). The gene discussed is LMO1; the disease is thymus lymphoma.