APC and myeloproliferative neoplasm: Thrombin and APC in the SVT MPN+ cohort were increased compared with healthy controls, with median levels of 0.49 vs. <0.46 pmol/L (p = 0.0012), respectively, 1.23 vs. 0.54 pmol/L (p = 0.0035), and compared with the SVT MPN− cohort, with thrombin levels of 0.49 vs. <0.046 (p = 0.0057) and APC levels of 1.23 vs. 0.58 (p = 0.0122).