KRT4 and age-related macular degeneration: The relevance of AMD RPE unique differentially expressed genes (FAM111B ZPLD1, KRT5, KRT5, SCUBE2, CD226, KRT4, KL4, and CYS1) to the eye or AMD is generally unknown, except for HIST1H2BC, which is downregulated in AMD RPE upon A2E challenge, and has previously been shown to be downregulated in aged mouse RPE (Dubey et al., 2024).