IL1RN and gastric cancer: The summary OR of gastric cancer risk associated with IL1B–511T, 231C, 13954T and IL1RN*2 was 1.26 (95 % CI: 1.03–1.55), 1.00 (95 % CI: 0.82–1.22), 1.37 (95 % CI: 0.94–2.00) and 1.20 (95 % CI: 1.01–1.41), respectively.