Extract: The search for alternative treatments for congestive heart failure remains an ongoing venture. Exciting research over the last 2 years has changed the long held dogma that the heart cannot regenerate itself. The work of many groups can be summarized by the following concept: increasing the number of CD117+ (c-kit+) stem cells in cardiac tissue or in the coronary circulation within 2 days of a myocardial infarction results in regeneration of myocardial tissue and improved cardiac function. Animal studies by Orlic, Anversa and colleagues have demonstrated that either the direct injection of bone marrow-derived CD117+ stem cells in the infarct border zone at the time of myocardial infarction, or mobilization of these stem cells prior to myocardial infarction results in regeneration of cardiac myocytes and improved left ventricular (LV) function. In a critical experiment, Itescu and colleagues extended the window of therapeutic opportunity by demonstrating that the intravenous infusion of bone marrow-derived stem cells 2 days after myocardial infarction led to decreased infarct size, increased vascular density and improved left ventricular function.