CCL2 and amyotrophic lateral sclerosis: Several cytokines have been proposed to play a role in ALS as reinforcing signals from glia cells, including interleukin-6 (IL6), tumour necrosis factor α (TNFα), monocyte chemoattractant protein-1, monocyte colony-stimulating factor (MCSF) and transforming growth factor β1 (TGFβ1) that were found increased in cerebrospinal fluid, plasma and epidermis from ALS patients, although with sometimes conflicting results [14].