Second, this meta-analysis did not find altered levels of pro-inflammatory cytokines IL-6 and IL-8, and anti-inflammatory IL-4 and IL-10 levels in patients with DS compared with HC subjects, the limitation of this meta-analysis is that the limited number of studies with a smaller sample size may have made observation of significant associations difficult for cytokine IL-4, IL-8, and IL-10. This evidence concerns the gene IL4 and Dravet syndrome.