The demonstration in the present study that type 1 DM prevents up-regulation of myocardial NRG-1β/ErbB expression in response to MI concomitant with an increased severity of HF further illustrates that the NRG-1β/ErbB system in the heart appears to be a local cardioprotective signaling system. The gene discussed is EGFR; the disease is myocardial infarction.