text: In autoimmunity the immune system wrongly recognizes certain native molecules in the body as foreign (self-antigen), and mounts an immune response against them. Since these native molecules, as normal parts of the body, will naturally always exist in the body, the attacks against them can get stronger over time (akin to secondary immune response). Moreover, many organisms exhibit molecular mimicry, which involves showing those antigens on their surface that are antigenically similar to the host proteins. This has two possible consequences: first, either the organism will be spared as a self antigen; or secondly, that the antibodies produced against it will also bind to the mimicked native proteins. The antibodies will attack the self-antigens and the tissues harboring them by activating various mechanisms like the complement activation and antibody-dependent cell-mediated cytotoxicity. Hence, wider the range of antibody-specificities, greater the chance that one or the other will react against self-antigens (native molecules of the body).