TLR4 and Parkinson disease: Our data also suggested that the MPTP‐induced PD mice had an obvious inflammatory condition in the colon, mainly in the increased expression of TLR‐4, p‐p65/p65, and pro‐inflammatory cytokines including IL‐1β, IL‐6 and TNF‐α, and suppressed p‐AKT/AKT (Figure 5).