Recent studies have identified tau cleavage by caspase activation at aspartate 421 (tau ΔD421) as an early event in the pathologic cascade leading to NFT formation [8, 9], a phenomena that has been observed in AD [9–12] and other tauopathies [13–15] and may contribute to pathogenesis and neurotoxicity [16]. This evidence concerns the gene MAPT and tauopathy.