JAK2 and Rare hereditary thrombophilia: JAK2 mutations were highly associated with both prevalent and incident VTE risk, with an OR of 6.58 (95% CI, 2.65-16.29; P = 4.7 × 10–5) and a HR of 4.2 (95% CI, 2.18-8.08; P = 1.7 × 10–5), respectively, consistent with the thrombophilia associated with JAK2-mutant MPN.