NRG1 and myocardial infarction: Attempts have been made to prolong the NRG1 half-life by using a controlled delivery22 or by combining it with adipose-derived stem cell transplantation.23 Second, a relatively small population (10%) of cardiomyocytes in the adult heart are mononucleated and although systematic administration of NRG1 initiates cytokinesis in vivo, it only corresponds to ~0.3% of the mononuclear cardiomyocytes present following MI.11 Third, the receptor presenting on the targeting cells has a vital role in managing whether the cells respond to NRG1 stimuli or not.