As shown in Figure 3, the expression of ACE2 in SAEC isolated from lung cancer patients without respiratory co-morbidities, lung cancer patients with asthma, and lung cancer patients with COPD was 0.041 ± 0.017, 0.057 ± 0.012, and 0.035 ± 0.011, respectively, with no significant differences between groups. This evidence concerns the gene ACE2 and chronic obstructive pulmonary disease.