By analyzing the data extracted from 30 full-text publications, we revealed that NOD2 rs2066844 C/T, rs2066845 C/G and rs2066847 (3020insC) polymorphisms might be associated with increased cancer risk especially for gastrointestinal cancer but no significant association was observed between NOD2 rs2066842 C/T polymorphism and cancer risk. The gene discussed is NOD2; the disease is cancer.