SPINK5 and Alzheimer disease: The single-nucleotide polymorphism c.1258A>G (rs2303067) in the SPINK5 gene is a multi-allele variant of which the risk allele A is the most frequent, with a frequency of 48% as reported by the gnomAD database; it causes the replacement of glutamine with lysine in position 420 (p.Lys420Glu) in LEKTI, and has been associated with atopy and atopic dermatitis, correlating with skin barrier functioning, disease severity, and a higher risk of food allergy [8,30,31], highlighting its role in AD susceptibility [29].