Increased levels of IL-17A (or IL-17) protein and messenger RNA were detected in the sputum [15, 40, 41], bronchoalveolar lavage fluids (BALF) [41], bronchial tissues [16, 42–44], peripheral mononuclear cells (PBMCs) [45, 46], and serum [17, 47, 48] from patients with asthma. The gene discussed is IL17A; the disease is asthma.