Patients harboring mutations of the JAK2 gene displayed elevated concentrations of total MPs (p < 0.001), RMPs (p < 0.01), PMPs (including PMPs with P-selectin co-expression, p < 0.001 for both), but similar levels of MMPs, GMPs and EMPs in comparison with ET patients harboring mutations of the CALR gene or triple-negative ET cases. Here, JAK2 is linked to essential thrombocythemia.