This low frequency, compared to the JAK2 V617F and CALR exon 9 mutations, may explain that while several, sensitive qPCR-based techniques have been described for detection of the MPL exon 10 mutations at diagnosis [11–13], there remains a lack of information regarding their utility as markers of MRD in these MPN. The gene discussed is JAK2; the disease is myeloproliferative disorder.