SORL1 and Alzheimer disease: Genome-wide association studies (GWAS) have found associations between AD and several genes involved in lipid homeostasis such as APOE (apolipoprotein E), CLU (clusterin, also known as apolipoprotein J), SORL1 (sortilin-related receptor 1) and ABCA7 (ATP-binding cassette, sub-family A, member 7) [3].