In this study, we discovered HSP90 inhibition by RGRN-305 robustly suppressed inflammation in experimental models of AD by significantly reducing clinical symptoms of dermatitis (erythema and oedema), immune cell infiltrations, expression of key cytokines (e.g., IL-4 and IL-13) and signalling pathways (STAT3 and STAT6) related to AD. This evidence concerns the gene IL4 and Alzheimer disease.