CCL4 and mucopolysaccharidosis: We found six inflammatory markers to be significantly elevated in children with MPS-IH when compared to controls: monocyte chemoattractant protein-1 (MCP-1) (mean 811 vs 328 pg/mL, p < 0.001), stromal cell-derived factor-1a (SDF-1a) (784 vs 200 pg/mL, p < 0.0001), interleukin-1 receptor antagonist (IL-Ra) (62 vs 6 pg/mL, p < 0.0001), macrophage inflammatory protein 1-beta (MIP-1b) (13.1 vs 3.3 pg/mL, p = 0.04), interleukin-8 (IL-8) (39 vs 17 pg/mL, p < 0.0001), and vascular endothelial growth factor (VEGF) (5.1 vs 0.1 pg/mL, p < 0.0001) as shown Fig. 4.