title: Relation of ABO blood groups to duodenal ulcer and bleeding.
mesh_terms: D000017:ABO Blood-Group System; D004381:Duodenal Ulcer / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D010438:Peptic Ulcer Hemorrhage / Q000276:immunology*; D012737:Sex Factors
chemical_list: D000017:ABO Blood-Group System