LMO2 is expressed in more than 50% of human T-ALL9,10 and LMO2 mRNA was found in 42% of pediatric/adult T cell leukemia (as judged from RNA-seq, with Fragments per Kilobase of transcript per million mapped reads (FPKM) values above 4)11, while it is not expressed in normal human/mouse peripheral T cells9,10,12, and the protein has no known functional role at this stage of T cell development13. The gene discussed is LMO2; the disease is T-cell leukemia.