As sleep time decreased (from 8 hours to 6 hours and 4 hours) the percent of patients with a stroke onset time <4.5 hours increased, the percent of patients in the MRI-based strategy with favorable stroke outcomes increased, and the percent in the MRI-based strategy treated with tPA despite a stroke onset time >4.5 hours decreased (to 15.1% and 11.9%, respectively). The gene discussed is PLAT; the disease is stroke disorder.