Activation of Janus kinase 2 (JAK2), frequently as a result of the JAK2(V617F) mutation, is a characteristic feature of the classical myeloproliferative neoplasms (MPNs) polycythemia vera, essential thrombocythemia, and myelofibrosis, and it is thought to be responsible for the constitutional symptoms associated with these diseases.
The JAK2(V617F) mutation load in hetero-/homozygous PV and EMGM is clearly related to MPN disease burden in terms of splenomegaly, constitutional symptoms and fibrosis.
In conclusion, a simple model which includes: age, JAK2 V617F-status and constitutional symptoms can clearly separate distinct risk groups and can be used in addition to the Lille model to predict OS after RIC-ASCT for myelofibrosis.