 Background: The identification of more than ten genes for familial Parkinson’s disease (PD) over the past years has pointed to important roles of the ubiquitin-proteasome system and of mitochondria for the pathogenesis of PD. Biochemical and molecular analyses of affected brain tissue from earliest disease stages has become possible through the generation of mice with mutations in such PARK genes. The translation of this research progress into diagnostics depends on the identification of biomarkers which are in common the familial PD variants and also to sporadic PD. Therefore, we screened practically all existing genes for expression changes reflecting the PD pathology.