APOE and Alzheimer disease: AD3 has a FAP-like profile due to the upregulation of genes involved in adipogenesis and lipid metabolism (ADIRF, THRSP, SCD, ACLY, FABP4, AGPAT2, APOE, and LPL), as well as ECM genes, such as CLU, VIM, and SPARC. Interestingly, AD3 also had a greater expression of mitochondrial-related genes, including ND4, ND1, COX1, COX2, and COX3, when compared to the other AD subtypes, which might indicate a brown adipose tissue-like profile, or be correlated with greater adipocyte lipogenesis and mitochondrial oxidative capacity in this specific subpopulation (Kaaman et al., 2007; Lu et al., 2018).