BPIFA1 and respiratory tract infectious disorder: Since several chronic respiratory diseases have been associated with low CC16 levels, including asthma (42, 43, 59–61), COPD (1, 6, 10, 46, 62–65), and cystic fibrosis (14), those individuals may be at an increased risk for respiratory infections due to loss of SPLUNC1 as well as low CC16.