Apoptosis, a form of cell death that is coordinated by a set of defined biochemical pathways, exists throughout the animal kingdom. Its critically important roles in development, homeostasis, and disease have made this a topic of intensive research and sometimes even more intensive controversy. One of these areas of controversy concerns the role of ceramide, produced by the hydrolysis of sphingomyelin. In this issue, Tepper et al. 2000 add to this debate with an interesting new theory.
When we consider the central mechanisms of apoptosis, we have two general questions to ask: first, what determines whether a cell will live or die? And if a cell is to die, what determines the precise form of this cell death? The second question is often as important as the first, as we'll see.
Evidence from early experiments showed that ceramide is...
