After 7 months of treatment (once weekly, 10 mg/kg), the treated 10‐month‐old MPS IIIA mice exhibited reduced CB2R and MCP‐1 expression in the plasma, reduced GFAP staining in the brain, and improved performance in a hanging test that accessed motor strength and coordination. The gene discussed is CCL2; the disease is mucopolysaccharidosis type 3A.