SOD2 and age-related macular degeneration: Comparison of control and AMD eyes showed 2–56 differentially expressed genes per cell type, including higher levels of heat shock proteins in RPE, lower levels of the antioxidant enzyme SOD2 in fibroblasts and vascular endothelial cells, and higher levels of the metabolic regulator PDK4 in macrophages and pericytes (Figure S5B; Data S4).