Consistently, the number of MAP2+/VGLUT1+ cells was significantly decreased in the AD patient iNs that expressed APOE ε4 at the amyloid-seeding stage (Fig. 1g, h), indicating that the conditional expression of APOE ε4 at the amyloid-seeding stage may affect the degeneration of AD patient iNs. Here, MAP2 is linked to amyloidosis.