LEP and amyotrophic lateral sclerosis: Surprisingly, several immune mediators (leukemia inhibitory factor (LIF), tissue inhibitor of metalloproteinase 1 (TIMP-1), tissue inhibitor of metalloproteinase 2 (TIMP-2), serum amyloid A (SAA), macrophage inflammatory protein-1 beta (MIP-1β), IFN-γ, TNF-α and monocyte chemoattractant protein (MCP-1)) were decreased in the plasma of ALS patients, coupled with a decrease in the metabolic sensor leptin.