Programmed cell death (apoptosis) is recognized, increasingly, as a contributing cause of cardiac myocyte loss with ischemia/reperfusion injury, myocardial infarction, and long-standing heart failure. Although the exact mechanisms initiating apoptosis in these in vivo settings remain unproven, insights into the molecular circuitry controlling apoptosis more widely suggest the potential to protect mammalian ventricular muscle from apoptosis through one or more of these pathways, by pharmacological means or, conceivably, gene transfer.