In this study we show that a trimeric recombinant fragment of SP-A is sufficient to neutralize the cytotoxic and proinflammatory effects of cathelicidin in alveolar epithelial cells, without affecting the microbicidal activity of LL-37 against K. pneumoniae, nontypeable H. influenzae, and P. aeruginosa, which can exacerbate COPD, asthma, and lung fibrosis and induce airway attacks in immunocompromised patients and the aged (88). Here, CAMP is linked to pulmonary fibrosis.