ELOVL4 and Alzheimer disease: In this study, dietary CAEP increased mRNA expression of fatty acid elongase (ELOVL4) and ceramide synthases (CERS2 and 3) in the dorsal skin of mice (Fig. 6B–D), especially CERS2 and 3 mRNA expression levels in CAEP group increased significantly than in the HR-AD and control groups (Fig. 6C and D).