By discriminating self from nonself and controlling the magnitude and class of immune
responses, the immune system mounts effective immunity against virtually any foreign
antigens but avoids harmful immune responses to self. These are two equally important and
related but distinct processes, which function in concert to ensure an optimal function of the
immune system. Immunologically relevant clinical problems often occur because of failure of
either process, especially the former. Currently, there is no unified conceptual framework to …