TLR2 is expressed not only in immune cells, but is also present in pulmonary alveoli and airway epithelial cells, suggesting that it plays a role in mucosal innate immunity and infection-induced lung injury (Charles et al., 2011; Hertz et al., 2003; Hoth et al., 2012; Jiang et al., 2005). Here, TLR2 is linked to infection.