IL4 and Alzheimer disease: AD is predominantly characterized byTh2 cytokines, such as IL-4 and IL-13, which impair keratinocyte antimicrobial peptide production and promote type 2 inflammation through keratinocyte-derived TSLP and IL-33 secretion (24, 41, 84, 91), mirroring prior reports by Guttman-Yassky et al.