BPIFA1 and chronic obstructive pulmonary disease: For example, in the current study, we found that baseline SPLUNC1 levels in apical supernatants of airway epithelial cells from COPD patients (18073 ± 2577 ng/ml) trended to be lower than those from normal subjects (24631 ± 2676 ng/ml, p = 0.14) and asthmatics (25020 ± 4480 ng/ml, p = 0.22).