To profile the pro- and anti-inflammatory cytokine-producing capacity of circulating B cells in Parkinson’s disease patients, we performed in vitro stimulation assays, using a standard B-cell stimulation consisting of CpG (a TLR9 agonist), CD40L (mimicking T-cell co-stimulation), ionomycin and PMA or alpha-synuclein fibrils (a disease antigen-specific stimulus) and measured IL10, a regulatory cytokine, or IL6, a pro-inflammatory cytokine (Fig. 5A and B for representative plots). Here, TLR9 is linked to Parkinson disease.