While several studies have implicated the proinflammatory cytokine TNFα as the critical link between elevated IOP and death of RGCs in glaucoma [22, 23, 48, 49], Nakazawa et al. demonstrated in a laser-induced mouse model of ocular hypertension that TNFα does not directly kill RGCs, but rather RGC death is dependent upon TNFR2-mediated activation of microglia [23]. Here, TNF is linked to glaucoma.