In support of this hypothesis, expression of Notch receptors was downregulated in clinical skin samples from AD patients (Dumortier et al., 2010) and gene expression analysis of publicly available microarray data revealed differential expression of Notch2, Notch3 and presenelin1 in patients with AD and psoriasis (Murthy et al., 2012). This evidence concerns the gene NOTCH2 and Alzheimer disease.