Analyses using a multilayer keratinocyte-based epidermal construct and mite fecal-antigen-induced AD-like dermatitis in an NC/Nga mouse model reported that IFN-γ decreases the mRNA levels of ELOVL1, ELOVL4, ELOVL6, and ELOVL7, and ceramide synthase, enzymes that are involved in elongation of fatty acid chains of ceramides and ceramide synthesis, and diminished levels of long-chain ceramides and fatty acids. This evidence concerns the gene ELOVL4 and Alzheimer disease.