The sputum inflammatory mediator profiles were distinct with increased TH2 (IL-5, IL-13, and CCL26) and TH1 mediators (CXCL10 and 11) in severe asthma compared with COPD and increased IL-6, CCL2, CCL3, and CCL4 in COPD compared with severe asthma. This evidence concerns the gene IL13 and chronic obstructive pulmonary disease.