PGC-1α, PGC-1β and PGC-1-related coactivators form a defense system against oxidative stress by upregulating the expression of antioxidant genes, such as SOD2 and thioredoxin 1 (TRX1), and the loss of function of this system can contribute to AMD initiation, increasing the formation of ROS by mitochondria and the accumulation of mitochondrial damage [142]. This evidence concerns the gene PPARGC1B and age-related macular degeneration.