CNTN2 and leukemia: A possible explanation for the failure of HTLV-1 LTR-Tax to induce leukemia in such animals may be provided by the observation that expression of this construct can be detected in various non-lymphoid organs like the brain, saliva glands, spleen, thymus, skin, muscle, bones and mammary glands [223,226] but not in the bone marrow [223].