F9 and thrombophilia: Regarding the risk for thrombosis, it may be subdivided into high risk, moderate and low risk thrombophilia; high risk thrombophilia includes antithrombin III, protein C and protein S deficiency, moderate risk thrombophilia consists of factor V Leiden, prothrombin gene mutation and factor VIII, and last but not least, low risk thrombophilia covers for factor IX, factor XI and hyperhomocysteinemia [19].