Third, although the findings in our study are supportive of early treatment with IFN, it does not deliver the definite proof, which would require a study, showing that early IFN‐treatment from the time of diagnosis influences hard clinical end‐points, such as risk of thrombosis and major bleeding, transformation to myelofibrosis and acute myeloid leukemia and ultimately survival. This evidence concerns the gene IFNA1 and myelofibrosis.