It is worth mentioning that autoimmunity, defined by the presence of autoantibodies and autoreactive lymphocytes does occur naturally. It appears that such naturally occurring autoantibodies and autoreactive lymphocytes are modulators for the suppression of early infections, clearance of apoptotic bodies, immune surveillance against cancer cells, among others, as reviewed in [160] . In this not yet completely unraveled system regulating immune response, the mechanisms responsible for the development of autoimmunity and autoimmune diseases remain enigmatic.