Scientific Essay from the year 2014 in the subject Medicine - Anatomy, Physiology, Cytology, grade: 1st, Imperial College London, language: English, abstract: Immune tolerance is the inhibition or absence of an immune response leaving only protective and beneficial immunity intact. Tolerance reduces response to both self and non-self antigens, which are substances which stimulate antibody production. Tolerance breakdown causes immune disease; failed self-tolerance causes incorrect identification of self as foreign, causing autoimmune disease. Failure of induced tolerance causes overzealous identification of harmless foreign substances as a threat, causing hypersensitivities. This essay explores the immunological mechanisms by which tolerance occurs, and their role in preventing the development of allergic disease.