JAK2 and myeloproliferative disorder: Similarly, the clinical image of myeloproliferative neoplasms was demonstrated to be dependent on the mutation order of ten-eleven translocation 2 (TET2) versus janus kinase 2 (JAK2): A JAK2 initial mutation increased the likelihood of presenting with polycythemia vera (as compared to essential thrombocythemia), with an increased risk of thrombosis and an increased sensitivity of JAK2-mutant progenitors to ruxolitinib in vitro (Ortmann et al., 2015).