DDC and vitiligo: The mRNA expression of DRD1 and DRD5, including GPX1, dopa decarboxylase (DDC), and monoamine oxidase A (MAOA), differs in vitiliginous skin, and the protein levels of DRD1, DRD5, DDC, MAOA, and MAOB vary in the skin and/or blood serum of patients with vitiligo [191].