An archetypal example is AD, a common inflammatory skin disease in childhood affecting nearly 20–30% of the population and is associated with skin barrier disruption linked with mutations in human skin barrier genes filaggrin (FLG), serine peptidase inhibitor Kazal type 5 (SPINK5), corneodesmosin (CDSN), and mattrin (TMEM79)72–74. This evidence concerns the gene CDSN and Alzheimer disease.