TLR2 and infection: Because the expression of choD has been shown to diminish Toll-like receptor 2 (TLR2) signalling (Klink et al. 2013), the lower expression of choD in clinical strains proves advantageous in that TLR2 signalling is not influenced in alveolar epithelial cells, and innate immunity is unhindered by the expression of this gene during infection.