Peptides from the plasma of patients with myocardial infarction promote endothelial cells to release both von Willebrand factor and endothelin-1; however, peptides from the plasma of patients with progressive unstable angina suppress the secretion of endothelin-1, and increase the secretion of von Willebrand factor and tissue plasminogen activator. The gene discussed is EDN1; the disease is myocardial infarction.