CCL4 and metachromatic leukodystrophy: MLD patients exhibit augmented levels of pro-inflammatory cytokines and chemokines including CCL2, IL-1Ra, IL-8, and CCL4 in the CSF, and sulfatides are known to influence a variety of immune cells, such as neutrophils, dendritic cells, B cells, and microglia in the CNS [27–29].