National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, USA.|Eppley Institute for Cancer Research, University of Nebraska Medical Center, USA.|National Center for Biotechnology Information, National Institutes of Health, USA.|Rutgers University Cancer Institute, USA.|Department Microbiology and Molecular Genetics, University of California, Davis, USA.|Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, USA.|National Center for Biotechnology Information, National Institutes of Health, USA.|Institute of Medical Genetics, Cardiff University, UK.