POLG and age-related macular degeneration: Two of three mitochondrial replication genes had significantly lower expression levels in AMD cybrids cocultured with the hRPC cells compared to the control and untreated AMD cybrids (Figure 4(a)): POLG (73.0% ± 3.3%, p = 0.015), POLRMT (78.9% ± 7.5%, p = 0.107), and TFAM (72.8% ± 3.0%, p = 0.025).