Analysis of the brain transcriptomes of mice with different APOE genotypes and previously published RNA sequencing (RNA-seq) data from the brains of human patients with AD and control subjects has shown that the expression of activating transcription factor 4 (ATF4), which is increased during the unfolded protein response (UPR), is significantly upregulated in the brains of AD patients25. Here, ATF4 is linked to Alzheimer disease.