Plasma quantitation of JAK2 mutation is not suitable as a clinical test: an artifact of storage

To the editor: JAK2V617F is a gain-of-function somatic mutation of JAK2 tyrosine kinase present in some but not all BCR/ABL-negative myeloproliferative neoplasms (MPN). High JAK2V617F allelic burdens correspond with homozygosity generated by uniparental disomy[1][1] present in some progenitors and