Bacterial infection leads to the activation of, e.g., TLR2 or TLR4, NOD1 or NOD1 expressed on AECs and subsequently to the release of proinflammatory cytokines, such as IL-1β, IL-6, and TNF, as well as of chemokines, such as CXCL8, CCL11, and CCL20. This evidence concerns the gene NOD1 and bacterial infectious disease.