IL-17A in migraine group [16.40 (16.16) pg/mL], in encephalitis with headache group [14.45 (11.76) pg/mL], and in pneumonia without headache group [3.45 (5.10) pg/mL] revealed that there were statistical differences in the overall distribution of IL-17A among the three groups (H = 39.40, p < 0.0001). This evidence concerns the gene IL17A and pneumonia.