title: Hepatitis B surface antigen in homosexuals.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006716:Homosexuality; D006801:Humans; D008297:Male; D008875:Middle Aged; D012749:Sexually Transmitted Diseases / Q000276:immunology
chemical_list: D006514:Hepatitis B Surface Antigens