HGF and myocardial infarction: Dual delivery of insulin like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) from affinity-bound biomaterial has previously shown to reduce apoptosis, induce cardiomyocyte cell-cycle re-entry and increase the incidence of GATA-4 positive cell clusters in a rat myocardial infarction model [24].Therefore it is interesting to study if endogenous IGF-1 and HGF are involved in the up-regulation of cardiac progenitors due to stress and if local administration of these growth factors could further potentiate this effect.