Immunohistochemical quantification of NGF expression in matched PN and AD patients (Supplementary Table 2) corroborated the RNA sequencing findings of hyperkeratosis in PN lesions compared to AD lesions (Figures 4A–D) and further revealed that PN lesional samples had higher dermal NGF expression than AD lesional samples (6.89 vs. 2.51% positive cells, p = 0.038) (Figures 4E–F). This evidence concerns the gene NGF and Alzheimer disease.