SNCAA53T/Gpx4+/fl double transgenic mice were bilaterally injected with adeno-associated virus–mediated (AAV-mediated) Cre recombinase constructs into the substantia nigra, to conditionally knockdown Gpx4 expression (A53T/Gpx4 CKD) before the onset of typical parkinsonism (Figure 5A and Supplemental Figure 5A). The gene discussed is GPX4; the disease is Parkinson disease.