No significant differences in GFAP/Tuj1 ratio were observed among the four groups of cerebral organoids by immunostaining (Supplementary Fig. 5A–B), RT-qPCR (Supplementary Fig. 5C), and western blotting (Supplementary Fig. 5D), suggesting that APOE4 or AD status leads to the higher apoE level without increasing astrocyte population in the cerebral organoids. Here, GFAP is linked to Alzheimer disease.