TLR1 and ulcerative colitis: Interestingly, in patients with ulcerative colitis, Pierik et al. [15] observed an association between TLR1 and TLR2 gene polymorphisms and pancolitis, and a negative relationship between TLR6 polymorphisms and pancolitis, suggesting that TLR2 and its co-receptors TLR1 and TLR6 are involved in the initial immune response to pathogens in the development of IBD.