Compared with smokers, 18 hub genes were identified in COPD patients, including GFM1, HSPBP1, MRPL15, RPL36, GNB2L1, RPL13, UBA52, CARS, EEF1G, RPL23A, RPS16, HSP90AA1, RPL32, RPS9, RPL13A, EIF5A, ETF1, and PSMA7 (Fig. 1B). This evidence concerns the gene CARS1 and chronic obstructive pulmonary disease.