RB1 and osteosarcoma: Consistent with that, our data showed loss of Trp53 and Rb1 in Ctsk-expressing cells significantly increased the expression of YAP/TAZ and their nuclear translocation, indicating an enhanced hyperactivation of YAP/TAZ in osteosarcoma caused by loss of Trp53 and Rb1 in Ctsk-expressing cells, as evidenced by our luciferase data showing that the transcriptional activity of YAP/TAZ increased 6.95-fold in the primary osteosarcoma cells compared to the normal cortical bone cells.