The authors [98] showed that administration of calcifediol to mice with induced AD significantly reduced keratinocyte proliferation and inflammatory cell infiltration, which was associated with inhibition of STAT3 phosphorylation and the AKT/mTOR signaling pathway, as well as with a reduction in the expression of the aquaporin 3 (AQP3) protein channel, which is crucial for maintaining the water balance of the epidermis. This evidence concerns the gene AQP3 and Alzheimer disease.