 TLR1 recognizes peptidoglycan and (triacyl) lipopeptides in concert with TLR2 (as a heterodimer).Toll-like receptors, including TLR-1, found on the epithelial cell layer that lines the small and large intestine are important players in the management of the gut microbiota and detection of pathogens.It is also found on the surface of macrophages and neutrophils.