Furthermore, hematopoietic cells expressing NOD2 were required to suppress colitis: irradiated wild-type mice transplanted with BM cells derived from NOD2-deficient mice developed severe colitis despite injection of MDP, whereas colitis development was markedly suppressed in irradiated NOD2-deficient mice transplanted with BM cells from mice with intact NOD2 [18]. Here, NOD2 is linked to colitis.