In a systematic review by Klettner et al., the potential role of TLR activation of RPE in the development of AMD was summarized into the following: complement activation, pro-inflammation and pro-angiogenesis, neuronal degeneration, reduced RPE cell functions (barrier function, phagocytosis, function in visual cycle), and RPE cell degeneration leading to more TLR4 activation [79]. The gene discussed is TLR4; the disease is age-related macular degeneration.