These factors included genes that were present in the standard DEG analysis and characterized in COPD in the literature: Prdx6 (30, 31), Selenbp1 (32), Ctsh (32, 33), Scgb1a1 (26), and Ndufs2 (34) (Figure 3, C and D). Here, NDUFS2 is linked to chronic obstructive pulmonary disease.