Although the Δ570–1175 and Δ570–1273 mutants developed T cell lymphoma only, it is currently unclear if there is a direct correlation with mutant MN1 expression because four lymphomas were GFP+ (one Δ578, one Δ570–1119, one Δ570–1175 and the one Δ578 mixed leukemia/lymphoma) while the others were GFP− (data not shown). Here, MN1 is linked to lymphoma.