The top three up-regulated proteins in COPD BALF EVs were Lactotransferrin (LTF, log2FC = 4.67, FDR = 1.57 × 10−13), Deleted In Malignant Brain Tumors 1 (DMBT1, log2FC = 4.45, FDR = 7.03 × 10−6), and Apolipoprotein A1 (APOA1, log2FC = 4.41, FDR = 2.75 × 10−10). Here, APOA1 is linked to chronic obstructive pulmonary disease.