MAPT and Alzheimer disease: Nevertheless, together with previous observations that Pb exposure induces elevated Aβ levels in rats110, increased Aβ plaque formation in monkeys111, and enhanced tau production and phosphorylation in both mice and monkeys112,113, our current results that Pb(IV) ions display specific binding to the Aβ peptide, alter its aggregation process, and cause oxidative effects in the presence of Aβ, clearly show that Pb ions can modulate the Aβ amyloid cascade events that are associated with AD.