MAPT and tauopathy: Proteolytic cleavage of tau at the K240-S241 peptide bond by GzmA followed by aminopeptidase activity could contribute to the formation of tau-CTF24, a 24 kDa C-terminal fragment of tau that was identified in the brains of Tg601 tauopathy mice and whose N-terminus was identified by mass spectrometry as L243 [16].