To comprehensively investigate the role of PGC genetic polymorphisms in altering the susceptibility to gastric cancer, we examined the individual effect of PGC tagSNP and its interaction with H. pylori infection on the risks of gastric cancer and its precursor, atrophic gastritis; and then preliminarily explored the influence of PGC tagSNP on its gene expression at both transcriptional and translational levels. The gene discussed is PGC; the disease is chronic atrophic gastritis.