PGF and myocardial ischemia: Therapeutic angiogenesis, including vascular endothelial growth factor (VEGF), placental growth factor (PLGF), fibroblast growth factor (FGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), angiopoietin (Ang) and erythropoietin (EPO), might be novel treatment options for IHD patients.