"Disorders such as Alzheimer???s disease (AD), Parkinson???s disease (PD), Huntington???s disease (HD), ALS and prion-protein diseases all share one common feature: accumulation and aggregation of misfolded proteins20,21 (see pages 774 and 803).Mediators of cell death induced by misfolded proteins have recently been identified (Box 2)." . . . . . .