Osteosarcoma can be induced with high efficiency in mice by osteoblast lineage specific deletion of the Trp53 gene, although the latency and penetrance is greatly enhanced by co-deletion of both copies of the Rb1 gene [51].These data are consistent with the centrality of TP53 and RB1 loss of function alterations in human osteosarcoma [23]. The gene discussed is RB1; the disease is osteosarcoma.