EXPLORE and HORIZON are phase II, multicenter, randomized, and controlled (treated vs. untreated patients) trials evaluating the safety and efficacy of GT005 in two different groups of patients with geographic atrophy (EXPLORE: patients with geographic atrophy secondary to AMD and with low CFI expression due to CFI variants; HORIZON: patients only with geographic atrophy secondary to AMD). The gene discussed is CFI; the disease is age-related macular degeneration.