Some researchs showed that PPARγ expression levels was reduced in lungs of patients with moderate and severe COPD [28], in macrophages gained from BALF of COPD patients when stimulated with IFN-γ [29], and in the skeletal muscle of COPD patients [30], whereas it was increased in the lungs of rats which treated with CS + Lipopolysaccharides (LPS) and patients with mild COPD. Here, PPARG is linked to chronic obstructive pulmonary disease.