In contrast with clinical trials for the treatment of DMD, hemophilia A and B, MPS type IIIB, and SMA, a clinical trial investigating X-linked retinitis pigmentosa (NCT03116113) did not observe any type of SAEs associated with liver enzyme levels after subretinal injection of cotoretigene toliparvovec (BIIB112/AAV8-RPGR).60 The gene discussed is RPGR; the disease is proximal spinal muscular atrophy.