UBB and Parkinson disease: We found that in the SN in our mouse model of the preclinical stage of PD, there were changes in the expression of a number of genes encoding enzymes of the synthesis and degradation of DA as well as proteins involved in the vesicular cycle and neurotransmission, axonal transport, degradation of proteins in the ubiquitin–proteasome system, neuroinflammation, and cell death.