In another study, Omar et al. assessed polymorphisms of the IL-1, IL-4, IL-6, and IL-10 gene cluster in a population of upper gastrointestinal cancers, including gastric cardia and non-cardia adenocarcinomas, esophageal squamous cell carcinoma and adenocarcinoma and in frequency-matched controls. Here, IL6 is linked to esophageal squamous cell carcinoma.