In this study, we hypothesized that SFC alleviated inflammation in patients with COPD by increasing the percentage of Foxp3+Tregs in the peripheral blood to enhance immune tolerance, thereby reducing the total numbers of cells and neutrophils in induced sputum, and reducing the levels of inflammatory factors such as IL-8, TNF-α, and IL-17A. This evidence concerns the gene FOXP3 and chronic obstructive pulmonary disease.