One possible explanation for the difference observed from the CSF and serum is that IL‐2, IL‐6, and IL‐10 might have a limited input in central nervous system (CNS) during the inflammatory process; as one previous study has shown, these cytokines are at similar levels in the CSF of ALS patients and control subjects (Tateishi et al., 2010). The gene discussed is IL6; the disease is amyotrophic lateral sclerosis.