IL1B and gastroesophageal reflux disease: Although several studies have suggested that IL-1β -511 and IL-8–251 polymorphisms are associated with the development of various gastroduodenal disease including GERD [20, 22, 24, 51–53], no statistically significant associations have been found between IL-1β -511 and IL-8–251 polymorphisms and GERD in this study.