The N-nitroso compounds mouse model of gastric cancer has been utilized to investigate various signaling pathways in gastric carcinogenesis, including the roles of p53 (Yamamoto et al., 2000), nuclear factor-kappa B (Sakamoto et al., 2010), the mitogen-activated protein kinase pathway (Shibata et al., 2008; Hayakawa et al., 2011), cyclooxygenase-2 (Takasu et al., 2008), β-catenin (Takasu et al., 2008), E-cadherin (Humar et al., 2009), and Kruppel-like factor 4 (Li et al., 2012); however, it is not considered a typical precancerous model. Here, PTGS2 is linked to gastric cancer.