During infection with bacterial pathogens airway epithelial cells can sense bacterial cell wall components via TLR2 (recognizing e.g., LTA), TLR4 (recognizing e.g., LPS), nucleotide-binding oligomerization domain-containing protein 1 (Nod1) and Nod2 (recognizing peptidoglycans) leading to activation of NFκB and subsequent immune responses and consequently to regulation of bacterial clearance (219, 220). Here, NOD1 is linked to infection.