(NP: 9.0 ± 2.6 nmol/L in COPD, 8.1 ± 2.6 nmol/L in asthma, and 7.8 ± 2.6 nmol/L in ACO versus 5.9 ± 2.7 nmol/L in the healthy controls, P < 0.05), as shown in Fig. 1C. Other inflammatory markers, including IL-10, IL-17, and IL-6, were comparable in all four groups. Here, IL6 is linked to chronic obstructive pulmonary disease.