realized that the immune system could go awry and, instead of reacting against foreign antigens, could focus its attack on self-antigens. He termed this con- dition\horror autotoxicus \We now understand that while mechanisms of self-tolerance normally protect an individual from potentially self-reactive lymphocytes, there are failures They result in an inappropriate response of the immune system against self-components termed autoimmunity In the 1960s, it was believed that all self-reactive lymphocytes
