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). Here, RPL27 is linked to Parkinson disease.