CXCR4 and myocardial infarction: After myocardial infarction, CD117+ MPCs migrate to the area bordering the infarction through the activation of HGF-c-met, SDF1-CXCR4, and IGF1-IGFR signaling mechanisms [24,25,26,27,28,29,30,31,32,33,34,35], thus providing protection and repair of damaged myocardium presumably by secretion of bioactive compounds [36,37,38,39].