Chemical. CAS 905586-69-8. Formula C18H16F2N6. MW 354.4. AZ-960 is a potent, selective and ATP-competitive JAK2 inhibitor that inhibits JAK2 kinase with a Ki of 0.45nM in vitro 3-fold selective over JAK3 and induces growth arrest and apoptosis in adult T cell leukemia ATL cells. Janus-associated kinases JAKs are cytoplasmic tyrosine kinases that are required for activating the signaling of certain cytokines and growth factor receptors. Many myeloproliferative diseases have been linked to a mutation in JAK2, where a switch from valine to phenylalanine occurs at position 617 V617F. Furthermore, constitutive activation of the JAK2 signaling pathway is associated with aggressive adult T cell leukemia/lymphoma. AZ-960 induces growth arrest and apoptosis of human T cell lymphotropic virus type 1, HTLV-1-infected T cells MT-1 and MT-2 in parallel with downregulation of the phosphorylated forms of JAK2 and Bcl-2 family proteins including Bcl-2 and Mcl-1.