title: On the hygiene hypothesis: regulation down, up, or sideways?
authors.forename: Torben
authors.initials: T
authors.lastname: Sigsgaard
authors.forename: Dick
authors.initials: D
authors.lastname: Heederik
mesh_terms: D000393:Air Pollutants / Q000276:immunology; D000485:Allergens / Q000276:immunology*; D004391:Dust / Q000276:immunology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology* / Q000517:prevention & control; D007114:Immunization; D008070:Lipopolysaccharides / Q000276:immunology*
chemical_list: D000393:Air Pollutants; D000485:Allergens; D004391:Dust; D008070:Lipopolysaccharides