TP53 and osteosarcoma: Similarly, many of the candidate genes implicated in the pathogenesis or progression of osteosarcoma in children have also been characterized in the canine disease, notably PTEN: phosphatase and tensin homolog, Rb: retinoblastoma, ezrin; villin-2, c-met: mesenchymal-epithelial transition factor, erbB-2: v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian) and p53: tumor protein 53 [7-12].