In the human immune system,<unk>  (also known as negative selection) is the process of eliminating any developing T or B lymphocytes that are reactive to self. Through elimination of autoreactive lymphocytes,<unk>  ensures that the immune system does not attack self peptides. Lymphocyte maturation (and<unk>  occurs in primary lymphoid organs such as the bone marrow and the thymus. In mammals, B cells mature in the bone marrow and T cells mature in the thymus.<unk>  is not perfect, so peripheral<unk>  exists as a secondary mechanism to ensure that T and B cells are not self-reactive once they leave primary lymphoid organs. Peripheral<unk>  is distinct from<unk>  in that it occurs once developing immune cells exit primary lymphoid organs (the thymus and bone-marrow), prior to their export into the periphery.
Central tolerance
Peripheral tolerance
Reverse tolerance
Desensitization 
Immune tolerance
Allergic response
Neural adaptation
Cross-tolerance