However, previous studies on pneumonia AECOPD, which is induced by Haemophilus influenzae and smoking, revealed a positive correlation between progression of the inflammatory disease and concentration of IL-17C in sputum, with no correlation with IL-17A and IL-17E30, suggesting that IL-17C may have unique functions compared to IL-17A. The gene discussed is IL17A; the disease is susceptibility to pneumonia measurement.