APP and early-onset autosomal dominant Alzheimer disease: Although the substrates of caspases represent a small minority of the overall proteomic makeup, in neurodegenerative diseases in general, and in Alzheimer's disease in particular, these substrates are over-represented: APP (and its related family members APLP1 and APLP2), the presenilins, and tau are all caspase substrates [28-32].