CASP6 and early-onset autosomal dominant Alzheimer disease: The active form of Casp6 and Tau cleaved by Casp6 (TauΔCasp6) are present in the three major neuropathological hallmarks of Alzheimer's disease: neuropil threads, neuritic plaques and neurofibrillary tangles in sporadic and familial forms of AD [33]–[35].