CCL2 and Alzheimer disease: MCP-1 is involved in macrophage recruitment into damaged tissue, but elevated expression has been shown to degrade the axonal myelin sheath (33–36, 71), and previous research has suggested that the post-TBI induction of MCP-1 may impose higher risk of AD due to the demyelination process that reduces the brain's resilience to subsequent neurodegenerative insults (29).