TLR4 and neuropathic pain: Our results indicate that Tanshinone IIA attenuates SNL-induced neuropathic pain, and the mechanism was caused, at least in part, by a blockade in the HMGB1-TLR4 pathway, presumably through the downregulation of HMGB1-TLR4 signalling, which plays a role in SNL-induced neuropathic pain.