Among the downregulated genes in PD (MSA-P > PD), key components included those involved in stress adaptation (HSP90AA1, GABRA6, NTRK3, DDX31), signal transduction (HSP90AA1, NTRK3, BTRC, PITPNM1, PPP2R2B), and ribosomal biogenesis (RPL27, DDX31) (Fig. 4E). The gene discussed is GABRA6; the disease is Parkinson disease.