Of the nominally significant proteins (Figure S9 in supporting information), several cytokines and immune‐related proteins (interleukin [IL]‐6, logFC = –0.668, P = 0.001; tumor necrosis factor [TNF], logFC = –0.299, P = 0.017; C‐reactive protein [CRP], logFC = –0.45, P = 0.018; IL‐15, logFC = –0.23, P = 0.027; IL‐9, logFC = 0.54, P = 0.49), amyloid peptides (Aβ38, logFC = –0.45, P = 0.004; Aβ42, logFC = –0.43, P = 0.011) and proteins implicated in synucleinopathies (PARK7, logFC = –0.912, P = 0.027; FABP3, logFC = –0.370, P = 0.036) were downregulated. This evidence concerns the gene IL9 and synucleinopathy.