JAK2V617F detection in progenitor and mature cell subtypes. An allele-specific PCR technique1 was used to detect the JAK2V617F allele in eBFUE, PBMNC, monocytes (CD14+), HSCs (CD34+, CD38−, lin−), and CMP (CD34+, CD38+, lin−) from a JAK2V617F-positive polycythemia vera patient. The mutant allele was not detectable in the T lymphocyte (CD4/8+) or B lymphocyte (CD20+) fractions.