MCP-3 belongs to the family of CC chemokines with potent chemotactic activities for several cell types, including monocytes, leukocytes, and dendritic cells. These chemokines exert their effects through interaction with the chemokine receptors CCR-1, CCR-2, CCR-3, and CCR-5. MCP-3 is expressed at sites of cellular injury, including the myocardium following an acute myocardial infarction, and is responsible for recruiting mesenchymal stem cells (MSCs) to the damaged tissue. Pre-clinical studies have shown that delivery of MCP-3 to hearts of rats experiencing chronic heart failure followed by intravenous infusion of MSCs significantly increased cardiac function compared to infusions of MSCs alone. MCP-3 has the potential to enhance the therapeutic potential of MSC treatment in a broad range of clinical indications.