While many publications highlight a role for SP-A in host defense against pathogens (reviewed in [16]), SP-A has been described as an important mediator in a variety of diseases including cystic fibrosis [17, 18], allergic rhinitis [19], sinusitis [20], lung cancer metastasis [21], pulmonary fibrosis [22], and more recently asthma ([3, 23, 24]) and COPD [25, 26]. This evidence concerns the gene SFTPA2 and asthma.