Some embodiments comprise methods, systems, and/or compositions comprising the production and/or use of one or agents selected from a group comprising microRNA-126, a promoter of microRNA-126 expression, a microRNA-126 mimic, cells such as human umbilical cord blood cells (“HUCBCs”), endothelial cells (“EC”), endothelial progenitor cells (“EPC”), and microRNA-126-enriched Exosomes/Microvesicles (“EMVs”) to promote, increase, or improve recovery from conditions, diseases, or injuries and/or function or outcome in a patient in need thereof.