Twelve patients with stroke in young age (≤ 45 years) who have no obvious cardio-embolic risk factors were selected for specific tests: transesophageal echocardiography (TEE), immunological tests (ANA, ANCA, anti-double strand DNA, anticardiolipin, and lupus anticoagulant), and thrombophilic profile (proteins C and S, antithrombin III, and factor V Leiden) (Table 4). Here, F5 is linked to Stroke.