For example, spinal nerve injury elevates the proinflammatory cytokine IL-1β in the central nervous system including the brainstem, thalamus/striatum and prefrontal cortex [54], and the increases of proinflammatory cytokine such as TNF-α or IL-1β in peripheral or brain are sufficient to produce neuropathic pain or depression [55]. This evidence concerns the gene IL1B and depressive disorder.