Table 2.

TLRs and their corresponding endogenous ligands

TLRs	Ligands and references
TLR2	Biglycan [29], endoplasmin [56], HMGB1 [74], HSP60 [52], HSP70 [53, 54], human cardiac myosin [38], hyaluronan [32, 63, 75] and monosodium urate crystals [72, 73]
TLR3	mRNA [68, 69]
TLR4	Biglycan [29], CD138 [23], α-crystallin A chain [57], β-defensin 2 [47, 48], endoplasmin [56], fibrinogen [30], fibronectin [27], heparan sulphate [28], HMGB1 [21, 41], HSP22 [57], HSP60 [51, 52, 60], HSP70 [53–55], HSP72 [58, 59], hyaluronan [32, 75, 76], monosodium urate crystals [72, 73], OxPAPC [71], resistin [61], S100 proteins [35, 36], surfactant protein A [62] and tenascin-C [37]
TLR7	RNA [66, 67] and small interfering RNA (siRNA) [70]
TLR8	Human cardiac myosin [38] and small interfering RNA (siRNA) [70]
TLR9	DNA [64, 65] and HMGB1[42]