MTRR and gastric cancer: To evaluate the effect of folate metabolism related genes polymorphisms on the prognosis of gastric cancer (GC), the genotype of seven single nucleotide polymorphisms (SNPs) of three genes were selected and genotyped in a cohort of 664 GC patients, including genes of Methylenetetrahydrofolate reductase (MTHFR), Methionine synthase reductase (MTRR), and Methionine synthase (MTR).