Kruskal-Wallis test among the three groups showed that the levels of IL-4, TNF-α, IL-17A, and IL-12p70 in children with migraine were higher than those in pneumonia without headache group, and the levels of IL-12p70 were also higher than those in children with encephalitis with headache and pneumonia without headache group. The gene discussed is IL17A; the disease is encephalitis.