TLR9 and colitis: Deletion of TLR4 [43,91], TLR2 [43,92], TLR5 [93] and TLR9 [90] as well as simultaneous deletion of TLR3 and TLR7 [12] led to disturbed epithelial homeostasis and enhanced susceptibility to acute DSS-induced colitis, however with less severe pathology than in MyD88-deficient mice.