title: Why standardized extracts?
mesh_terms: D000485:Allergens / Q000592:standards*; D006801:Humans; D007167:Immunotherapy; D007394:International System of Units; D012015:Reference Standards; D014020:Tissue Extracts / Q000592:standards*; D014944:World Health Organization
chemical_list: D000485:Allergens; D014020:Tissue Extracts