The growth-promoting properties of truncated BCL11B variants isolated from leukemic cells [20], the losses of heterozygosity at the very early stages of lymphomagenesis [31] and detection of BCL11B haploinsufficiency for suppression of mouse thymic lymphomas [29], [32] support the speculation of BCL11B tumor suppressive activity. The gene discussed is BCL11B; the disease is neoplasm.