The levels of pT231, but not pS202, were significantly increased in 3 × Tg-AD mice treated with saline/icv-STZ compared to saline/icv-saline mice (P < 0.05; Fig. 2A and C and Fig. S2A-B), and PS128 supplementation prevented the increase in levels the pT231 tau protein (P < 0.05; Fig. 2A and C). Here, MAPT is linked to Alzheimer disease.