It has been shown that the TLR4-dependent production of pro-inflammatory cytokines is increased in POAG tears [135], AH [136], and in the ONH astrocytes in glaucoma models, indicating astrocyte paracrine and autocrine inflammatory signaling is increased across multiple tissues during glaucoma progression, making astrocyte activation a key instigator of ONH RGC damage [35,44,134]. Here, TLR4 is linked to open-angle glaucoma.