Levees of immunological tolerance.

Immunological tolerance guards against spurious immune responses to body constituents. Tolerance encompasses a network of mechanisms: central and peripheral, cell-autonomous and cell-interactive. Our understanding of these mechanisms has improved greatly over recent years, often reflecting new insights into the processes underlying particular autoimmune diseases. Yet it is possible that important tolerance mechanisms remain to be discovered, perhaps an explanation for the so-far disappointing clinical translation to the prevention and cure of autoimmune diseases.