Stroke is the third leading cause of death and a leading cause of adult disability in the United States and worldwide. To date, the only scientifically-proven and FDA-approved treatment for acute stroke is the clot-busting drug, tissue plasminogen activator (tPA). A newer clot-busting drug, tenecteplase (TNK), has chemical properties that make it a potentially safer and more effective drug for treating stroke. Preliminary testing of TNK in patients with acute stroke has been encouraging enough to warrant further testing.