The expression of JAK2 mutation is seen in all conditions, EXCEPT:
Polycythemia vera (PV), Primary myelofibrosis (PMF) and Essential thrombocytosis (ET) are characterized by expression of a JAK2 mutation, V617F. It causes constitutive activation of tyrosine kinase. PV, PMF, and ET are transformed into acute leukemia very rarely. Ref: Harrison, Edition-18, Page-898
Chronic eosinophilic leukemia
Primary myelofibrosis
Polycythemia vera
Essential thrombocytosis