In fact, although gambierol exhibits a potent acute lethal toxicity in mice (minimal lethal dose: 50 μg/kg, ip), its tetracyclic truncated analogue in a mouse model for AD induces a decrease of amyloid β1−42 level, a reduction of tau phosphorylation, and a reduction in the N2A subunit of the N-methyl-D-aspartate (NMDA) receptor level [92]. Here, MAPT is linked to Alzheimer disease.