Although we did not identify significant differences in levels of cis-UCA in suction blister fluid between the groups (see Fig E5 in this article's Online Repository at www.jacionline.org), a statistically significant stepwise decrease in total epidermal UCA levels from healthy control subjects to WT subjects with AD, FLG-null heterozygotes with AD, and FLG-null homozygotes with AD has been reported based on a tape-stripping method to determine UCA levels in the epidermis.37 This evidence concerns the gene FLG and Alzheimer disease.