Duchemin et al. (2010) assessed the circulating procoagulant activity of plasma collected from MPN subjects, demonstrating that this parameter was elevated (particularly in JAK2 V617F-positive cases with a homozygous genotype), whereas endogenous thrombin potential was reduced, in MPNs versus healthy subjects (p < 0.001 and p = 0.004, respectively). The gene discussed is JAK2; the disease is myeloproliferative neoplasm.