The contribution of alcohol consumption behavior to gastric cancer risk was at a slightly increased level for those people without 1G allele at MMP1 promoter -1607 polymorphic site (OR = 1.22, 95% CI = 0.51-2.89, P = 0.6593), while for those with alcohol consumption behavior and 1G allele at promoter -1607, no synergistically increased moter -1607 gastric cancer risk was found (OR = 1.44, 95% CI = 0.80-2.58, P = 0.2223) (Table 4). Here, MMP1 is linked to gastric cancer.