RNA sequencing (RNAseq) and T-cell receptor (TCR) analysis confirmed monoclonality of leukemic disease (Fig. 1E) and detected elevated expression of canonical oncogenic transcription factors (Van Vlierberghe and Ferrando, 2012) in individual T-ALL cases, in particular Tal1, Lyl1 and Lmo2 (Fig. 1F). The gene discussed is TAL1; the disease is acute lymphoblastic leukemia.