The qRT-PCR analyses showed that CD39 was significantly downregulated in the COPD group compared with both the NOS and NS groups (1.17 [0.85–1.81] vs 1.88 [1.35–4.41] and 3.32 [1.23–5.39], respectively, p = 0.037) (Fig. 1). The gene discussed is ENTPD1; the disease is chronic obstructive pulmonary disease.