RB1 and cancer: For instance, canine osteosarcoma closely recapitulates key features of pediatric human osteosarcoma, including a propensity for lung metastasis, a relatively low point mutation burden, complex chromosomal rearrangements, and recurrent genetic aberrations involving critical cancer-related genes such as Tumor Protein 53 (TP53), Retinoblastoma 1 (RB1), SET Domain Containing 2 (SETD2), and components of the Phosphatidylinositol 3-Kinase (PI3K) and Mitogen-Activated Protein Kinase (MAPK) signaling pathways (Gardner et al., 2019).