"Mutations in the Crumbs homologue 1 (CRB1) gene cause photoreceptor degeneration resulting in progressive retinitis pigmentosa (RP) or Leber congenital amaurosis (LCA), which both currently are untreatable blinding diseases. CRB1 is localized in Mueller glia cells at a subapical region (SAR) adjacent to adherens junctions between Mueller glia cells and photoreceptors. Loss of CRB1 function result ...