TLR2 and rheumatoid arthritis: Lu et al. (2021) demonstrated that celastrol treatment inhibited the release of inflammatory cytokines, such as TNF-α, IL-6, and IL-1β in the collagen-induced arthritis (CIA) animal model and suppressed RA-induced cellular autophagy by inhibiting the activation of the TLR2/HMGB1 signaling pathway.