CD1A and Alzheimer disease: In contrast, the enzymes of the elongation of very long (ELOVL) fatty acid family, proposed to be involved in the process of fatty acid extension for CD1a ligands (48), were not differentially expressed in the in vitro models, whereas we observed downregulation of ELOVL1, ELOVL3, ELOVL4, and ELOVL5 mRNA in AD skin (Figures 8F–I).