The CC chemokine ligand 2 (CCL2; previously known as monocyte chemotactic protein-1, MCP-1) is of particular interest in brain trauma because it is a potent activator of the CC chemokine receptor 2 (CCR2) [7, 8], which beyond inducing a chemotactic response in macrophages, monocytes, and microglia [9, 10], may also have a direct effect on blood-brain barrier permeability [11, 12]. The gene discussed is CCL2; the disease is brain injury.