 In addition, oncogenic JAK3 mutations have been identified in acute megakaryoblastic leukemia, T-cell prolymphocytic leukemia, and juvenile myelomonocytic leukemia and natural killer T-cell lymphoma (NK/T-lymphoma).Most mutations are located in the pseudokinase and kinase domain of the JAK3 protein.Most JAK3 mutations are dependent on JAK1 kinase activity for their transforming capacities.