To understand the cell-type-specific regulation of APOE levels in the human brain, we analyzed single nucleus RNA-seq data from 46 human postmortem brain DLPFC (European ancestry) focusing on six major cell types (see methods in Supplementary file and Fig. S19), we found that APOE was significantly upregulated in microglia of AD patients compared to healthy persons in the evaluation of neurofibrillary tangle using braak criterion, amyloid plaque using CERAD criterion, cognitive impairment by MCI and cogdx (Supplementary Fig. S20A, B, C, Table S14). Here, APOE is linked to amyloidosis.