As vitamin D has been shown to increase the expression of cathelicidin, its supplementation has been used as a relatively simple means to enhance LL-37 in the pulmonary compartment, leading to decreased risk of microbial infections and thus to exacerbation in such clinical settings such as COPD [29,32,64,71] and asthma [29,30,31,60]. The gene discussed is CAMP; the disease is asthma.