CXCL12 and acute myocardial infarction: Various types of stem cells and progenitor cells have been successfully used in the experimental acute myocardial infarction models.9 We speculated that, besides stem/progenitor cells being involved in intimal repair, their abnormal implantation in the neo-intima may be the main cause of vascular restenosis, in which SDF-1, an important chemokine, plays a crucial role.