Vandenbroucke et al. found the incidence of venous thrombosis to be 0.8 per 10,000 person-years and 3.0 per 10,000 person-years for non-OCP users and OCP users, respectively, and the relative risk of venous thrombosis to be 3.8 (95% CI 2.4–6.0) for OCP users and even higher for patients with the factor V Leiden mutation [19]. The gene discussed is F5; the disease is Venous thrombosis.