After retrieving the full text of these 29 articles, we excluded 9 articles because of the following reasons: one reported the association between the NQO1 609C>T SNP and H. pylori seropositivity [54]; one did not focus on the NQO1 609C>T but on NQO1 R139W SNP (rs4986998) [55]; three were for the association between the NQO1 609C>T SNP and colorectal adenoma [56], [57], [58]; two were for the correlation between the NQO1 609C>T genotypes and NQO1 activity [59] or telomere length [60]; two were for review or meta-analysis articles [61], [62]. Here, NQO1 is linked to colorectal adenoma.