Two, N-acylethanolamine acid amidase (NAAA) and PTK7 were selected for further validation based on the following criteria: (a) the prominent alteration between aggressive and nonaggressive PC, (b) the positive staining in Human Protein Atlas in PC tissue, (c) novelty, and (d) the prediction of signal peptide for secretion. Here, PTK7 is linked to pachyonychia congenita.