IL9 and respiratory system disorder: Of the 27 cytokine levels examined in the present study, 14 BALF cytokines or chemokines, including IL-5, IL-6, IL-7, IL-8, IL-9, IL-15, IL-17, IP-10, Eotaxin, FGF-basic, MIP-1α, PDGF-bb, RANTES, and TNF-α, were found to be different among the three respiratory disorders, while the other 13 cytokines were not obviously different.