The human cathelicidin LL-37 has been shown to promote bacterial clearance in murine pulmonary infection models (33, 34), and Camp−/− mice have increased susceptibility to bacterial infection in a wide range of organs, including skin (17), intestinal tract (35), urinary tract (36), cornea (37), and lung (34, 38), demonstrating the critical, nonredundant role for cathelicidin in murine host defense against bacterial infection. Here, CAMP is linked to bacterial infectious disease.