We also confirmed that the number of EEA1- and Aβ42-positive puncta are also increased in APOE ε4-expressing AD patient iNs, suggesting that APOE ε4 induction influences Aβ oligomeration via APP endocytosis and processing in AD patient iNs (Additional file 1: Fig. S5d). Here, EEA1 is linked to Alzheimer disease.