Genetic abnormalities in procoagulant factors (e.g., Factor V Leiden, leading to APC-resistance and prothrombin G20210A leading to elevated levels of prothrombin) are common variants with an overall incidence of carriers of 2–5% among Caucasians and they are found in 6–20% of patients with deep vein thrombosis [102–106]. Here, F5 is linked to deep vein thrombosis.