ETP-ALL has a lower frequency of classical T-ALL genetic alterations such as NOTCH1/FBXW7/CDKN2A mutations [10] and a higher prevalence of FLT3, NRAS/KRAS, DNMT3A, IDH1, IDH2, JAK3, and ETV6 mutations and changes associated with acute myeloid leukemia (AML) [10,15], which confirms the different genomic profile of this subgroup. The gene discussed is JAK3; the disease is acute lymphoblastic leukemia.