We expressed the RNAi constructs under the control of glass multiple reporter (GMR-GAL4 driver), which expresses late during eye development and posteriorly to the morphogenetic furrow.42 Thus, we confirmed that Cul4 downregulation suppresses retina degeneration due to spastin RNAi-mediated downregulation (Supplementary Fig. 4A–C). The gene discussed is SPAST; the disease is retinal degeneration.