To further test whether the transcriptional activity of YAP/TAZ was increased in Trp53 and Rb1 ablated osteosarcoma cells, we directly measured the transcriptional activity of YAP/TAZ transfecting normal cortical bone cells or primary osteosarcoma cells with the 8xGTIIC-luciferase reporter, which carries eight copies of the minimal TEAD-binding sequences [32]. Here, RB1 is linked to osteosarcoma.