Capase 6 enzyme, molecular model. Caspases are proteases, enzymes that cleave proteins and play a role in apoptosis (programmed cell death). Caspase 6 forms part of the capase activation cascade, and is processed by other capases during the process of apoptosis. It is also thought to play a role in neurodegenerative conditions such as Alzheimer's disease and Huntington's disease. It is being studied as part of research into treatments for this conditions. The structure of four protein chains is highlighted here by the colours.