S100A8 and gastric cancer: Mechanistically, estradiol has been shown to promote epithelial–mesenchymal transition in GC cells, an effect further potentiated by coinfection with CagA-positive H. pylori,[35] which aligns with our subgroup analyses demonstrating stronger associations between estrone and high-grade lesions or GC in CagA-positive individuals (OR continuous = 7.34).