This “rough-eye” phenotype has been observed in Drosophila models of neurodegeneration, including Alzheimer’s disease and PD.29,30 Flies carrying a heterozygous null variant in Dap160 (the Drosophila ortholog of ITSN1)31 had exacerbated α-synuclein-induced degeneration, with more severe disorganization covering a larger eye area (Figures 4C and 4D). The gene discussed is ITSN1; the disease is early-onset autosomal dominant Alzheimer disease.