IL6 and Parkinson disease: Following 6‐OHDA injection, levels of pro‐inflammatory cytokines were significantly increased in the PD model (TNF‐α: p < .001; IL‐1β: p < .001; IL‐6: p < .001; Figure 5d–f), whereas calcitriol pretreatment prior to 6‐OHDA injection significantly reduced pro‐inflammatory cytokines release (TNF‐α: p = .002; IL‐1β: p = .033; IL‐6: p = .004; Figure 5d–f).