The second objective was to employ RB1 molecular deletion and microsatellite-based linkage analysis as laboratory tools , while counseling families with a history of retinoblastoma ( RB ) .
O O O O O O B-GeneOrGeneProduct O O O O O O O O O O O O O O O O O B-DiseaseOrPhenotypicFeature O B-DiseaseOrPhenotypicFeature O O