Absent in normal and hyperplastic prostates, PECAM-1 (platelet endothelial cell adhesion molecule-1), VEGF, and Tie-2 (receptor tyrosine protein kinase-2) proteins are expressed in canine PC, with basal and secretory cells exhibiting increased expression for FGF-2 (fibroblast growth factor-2) [170]. This evidence concerns the gene PECAM1 and pachyonychia congenita.