Mice that are deficient of nuclear receptors (NRs) retinoid X receptor α (RXRα), vitamin D receptor (VDR) or Notch1 in epidermal keratinocytes, exhibit epidermal permeability barrier (EPB) defects, express elevated levels of TSLP in skin, and subsequently develop AD-like phenotypes [10], [12]–[14]. Here, VDR is linked to Alzheimer disease.