TAL1 and acute lymphoblastic leukemia: Based on ectopic expression of known T-ALL drivers, we classified this subset of 13 patients into the following subgroups: TAL1/2 (n = 5), TLX1/3 (n = 3), HOXA (n = 2), NKX2‐4/5 (n = 2), and LMO2 (n = 1; Fig. 3A).