Further assessments to determine the presence of a prothrombotic state include the JAK2 mutation, with or without myeloproliferative disorders, prothrombin gene mutation, antithrombin deficiency, paroxysmal nocturnal haemoglobinuria, and vasculitis, which encompasses Behcet’s disease, methylene tetrahydrofolate reductase deficiency, and genetic mutation of plasminogen activator inhibitor-1. The gene discussed is JAK2; the disease is vasculitis.