The brown module has 53 hub genes, including genes associated with dopaminergic signaling (GNB1, GSK3B), long-term potentiation (PPP1CB), opioid signaling (PPP2CA, PPP3CA, PPP3R1), epilepsy (SYN1), and Parkinson’s disease (SNCA). The gene discussed is PPP2CA; the disease is Parkinson disease.