For conformational alterations of tau following its abnormal phosphorylation is generally regarded as an underpinning for the formation of neurotoxic aggregates that wreak havoc in the tauopathies, and that the P301L p-tau consistently showed stronger propensities of aggregation and killing tissue culture cells (Figure 2, Figure 3, and sections below), we wondered whether the presence of a smaller species of the P301L p-tau was indicative of a unique conformation of this mutant form that was particularly amenable to proteolysis. This evidence concerns the gene MAPT and tauopathy.