For example, in the classic TLR2/4 mice, after ischemic stroke, TLR2/4 binds to the endogenous ligand HMGB1, activating a series of signal transduction cascades, which then produce pro-inflammatory cytokines affecting the prognosis of ischemic stroke (Tajalli-Nezhad et al., 2019; Qiu et al., 2019). Here, TLR2 is linked to ischemic stroke.