TGFB1 and age-related macular degeneration: Many questions remain unanswered that will need to be addressed in future investigations, including the differential contributions of EMT and EndMT to the mesenchymal cell population in subretinal fibrosis, any potential synergistic activity between EMT and EndMT in AMD and the controversial dual role of TGFβ as both a pro- and anti-angiogenic factor in different clinical stages of AMD.