Compared with blood group non-O, blood group O was associated with a higher risk of pancreatic cancer (OR =  1.32; 95% CI: 1.22, 1.42), CagA endemic pancreatic cancer (OR =  1.20; 95% CI: 1.11, 1.30), and CagA-nonendemic pancreatic cancer (OR =  1.42; 95% CI: 1.28, 1.59). The gene discussed is S100A8; the disease is pancreatic neoplasm.