IL-4, IL-5, IL-10, and IL-13 are the main cytokines excreted by Th2 cells, and neurotrophic factor brain derived neurotrophic factor (BDNF) and NT-3 are also produced by Th2 cells, which play critical roles in GBS and EAN etiology as well (23). This evidence concerns the gene IL10 and Guillain-Barre syndrome.