A pre/post style observational study was undertaken after the organization of the Thammasat Stroke Network (TSN). The main outcome measures included favorable outcome of the patients treated with intravenous tissue plasminogen activator (tPA) at 3 mo and symptomatic intracerebral hemorrhage by comparison between walk-in patients and the patients who were referred by the TSN. This evidence concerns the gene PLAT and intracerebral hemorrhage.