JAK1 and acute lymphoblastic leukemia: Additional known T-ALL driver genes also found to be mutated in our cohort include KDM6A/UTX (3.4% vs. 4.5–14%) [33, 28], JAK1 (3.4% vs. 4.5%) [33], PTPN2 (3.4% vs. 3.6%) [33] and LEF1 (6.9% vs. 7.2–17.0%) [33, 43].