Remarkably, while suppressing neurofibromas, genetic deficiency of NF-κB1 promotes immortalization of Tax-expressing macrophages and causes massive infiltration of neoplastic macrophages into the spleen, lymph nodes and adrenal glands, resulting in splenomegaly, lymphadenopathy and adrenomegaly in mice. The gene discussed is CNTN2; the disease is neurofibroma.