The biological role played by a material entity when bound by a receptor of the adaptive immune system. Specific site on an antigen to which an antibody binds.
Any nutrient required in small quantities by organisms throughout their life in order to orchestrate a range of physiological functions.
A chemical compound, or part thereof, which causes the onset of an allergic reaction by interacting with any of the molecular pathways involved in an allergy.
(via metal allergen )