Six months after DEN injection, compared with untreated group, MDP treatment significantly increased the tumor incidence (40.0% (6/15) vs. 80% (12/15)) and tumor burden (tumor number: 4.67 ± 0.82 vs. 10.83 ± 1.85, P < 0.01; tumor size: 7.12 ± 2.04 vs. 11.58 ± 2.13, P < 0.01), in the WT, but not in Nod2△hep (tumor incidence: 27.8% (5/18) vs. 33.3% (5/15); tumor number: 2.2 ± 0.84 vs. 2.40 ± 1.14, P > 0.05; tumor size: 2.00 ± 0.71 vs. 3.60 ± 1.14, P > 0.05), indicating that MDP promotes tumorigenesis in an NOD2-dependent manner. This evidence concerns the gene NOD2 and neoplasm.