PDE6C and Alzheimer disease: We examined different retinal cell markers (Kim et al., 2023) and found cone-specific markers were downregulated in RDH12-AD retinal organoids compared to the unaffected control: OPN1LW, TDRG1, GRK7, RAB41, MYL4, PDE6H, CNGB3, PDE6C, GNAT2, GUCA1C, GNGT2, ARR3, SLC24A2, KCNB2, and PEX5L (Supplementary Table S4; Figure 4A).