For Alzheimer’s disease, cerebral organoids were prepared from hiPSCs that harbored the disease causing variant of apolipoprotein E (APOE4), which was found to show ∼2 fold increase in the accumulation of amyloid β than control organoids that had the APOE3 gene variant (Lin et al., 2018). The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.