IL6 and metachromatic leukodystrophy: In this investigation we included macrophage inflammatory protein-1α (MIP-1α), the first cytokine that is upregulated in the disease progression of MLD mice, five cytokines being elevated at end-stage disease [MIP-1β, monocyte chemotactic protein-1 (MCP-1), RANTES, interleukin-1β, interleukin-6], and the two classical proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) both of which remain unchanged in MLD mice (22).