Variants of the MDR1/ABCB1 gene have been associated with susceptibility to UC. TLR2/MDR1A double-knockout mice presented exacerbated colitis score, which could be inhibited by treatment with IL-1R antagonist; intestinal CD11b+ Ly6C+-derived IL-1β production and inflammation was dependent on MyD88. Here, IL1R1 is linked to colitis.