PD up‐regulated genes included transcription factor E2F2, implicated in hemisphere‐dependent PD pathology55 and neuroinflammation after spinal cord injury,56 Glutathione‐specific gamma‐glutamylcyclotransferase‐1 (CHAC1), reported to regulate unfolded protein response57 and linked to paraquat‐induced neurotoxicity,58 and CXCR4, a chemokine receptor linked to neuroinflammation which is expressed in dopaminergic neurons.59 This evidence concerns the gene CXCR4 and Parkinson disease.