IUPAC definition : Selective reaction of the body to substances that are foreign to it, or that the immune
system identifies as foreign, shown by the production of antibodies and antibody-bearing
cells or by a cell-mediated hypersensitivity reaction.;
Selective reaction of the body to substances that are foreign to it, or that the immune
system identifies as foreign, shown by the production of antibodies and antibody-bearing
cells or by a cell-mediated hypersensitivity reaction.