As expected, we found that expression of Trp53 and Rb1 was significantly decreased in the chondrosarcoma and chondrosarcoma-invaded tissues compared to controls (Supplemental Fig. S2A–C), suggesting the chondrosarcoma formation and lung metastasis was directly caused by loss of Trp53 and Rb1 in chondrocytes. Here, RB1 is linked to chondrosarcoma.