CASP3 (Caspase 3) is a cysteine-aspartic acid protease involved in the execution-phase of cell apoptosis. In axonal injury, CASP3 mediates the cleavage of amyloid-beta 4A precursor protein which results in amyloid beta peptide deposition. Activation of CASP3 is correlated with neuronal death and functional decline in Alzheimer's disease. CASP3 is also vital for the development of the normal brain, and is involved in embryonic and hematopoietic stem cell differentiation. Alternative splicing of this gene results in two transcript variants that encode the same protein. In immunohistochemistry, CASP3 has high cytoplasmic positivity in lymphoid tissues, and is found in most other tissues throughout the body. References: J Neurotrauma. 2002 May;19(5):601-14, PMID: 12042095; Brain Res. 2001 Apr 20;898(2):350-7, PMID: 11306022; Cell. 1999 Apr 30;97(3):395-406, PMID: 10319819; Cell Stem Cell. 2 (6): 515–6, PMID: 18522841;