Caspase-3 is a cysteine-aspartate protease that plays a key role in apoptosis and is widely used as a biomarker of apoptosis. caspase-3 is sheared into two fragments with molecular weights of 17 kDa (p17) and 12 kDa (p12) during apoptosis and translocated to the nucleus. caspase-3 is activated by shearing Caspase-3 is involved in the degradation of Huntington's protein. caspase-3 is involved in the cleavage of amyloid precursor protein, which is associated with neuronal death in Alzheimer's disease.