The downregulation of key proteins involved in oxidative stress and neurodegenerative diseases, encoded by PARK7, GLO1, GLUD2, VDAC2, UQCRC1, and UNC5C, including the 20S proteasome core complex proteins, highlights a possible mechanistic link to xerostomia pathophysiology. The gene discussed is UQCRC1; the disease is neurodegenerative disease.