MAPT and proteostasis deficiencies: To examine whether the P301L mutation confers specific molecular characteristics that may be different from the wildtype p-tau, we first tested the inducer-free aggregation of mutant P301L p-tau along with the wildtype and the unphosphorylated counterparts with thioflavin S (ThS), which emits fluorescence upon binding the amyloid structure that is shared by many proteopathy proteins, including tau, to assess whether the P301L mutation could affect the kinetics of tau aggregation [41].