SOD2 and age-related macular degeneration: Moreover, transgenic animal models have been studied in AMD over the last few years, such as the nuclear factor-erythroid 2-related factor 2 (Nrf2) knock-out (KO) mouse model, the peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) KO mouse model, the superoxide dismutase-2 (SOD2) KO mouse model and the peroxisome proliferator-activated receptor-β (PPARβ) KO mouse model [55,56,57].