To determine whether sensing of gut bacteria via TLR4 or TLR2 has a general impact on the composition of the intestinal microflora (which could influence the outcome of colitis), we performed a global molecular survey of the colon microbiota in healthy C57BL/10 mice lacking TLR2, TLR4, or both receptors (Figure 3). The gene discussed is TLR2; the disease is colitis.