SORL1 and Alzheimer disease: The list of APOE2 specific genes is the largest one (241 genes) and include mitochondrial transporters such as SLC25A3 and SLC25A4. APOE3 specific signatures included MAPT and APP genes, along with other neuronal genes such as the cholinergic receptors CHRNA10 and CHRNA2. APOE4 specific genes included known AD genes involved in vesicle transport such as CLU and SORL1; SORL1 has been shown to regulate IL6 levels, also identified among APOE4 specific signatures.