identified consistent amplification of the FRS2 gene in 57 WDL/DDLs (100%) (35).Subsequently, our research found a high amplification frequency of the FRS2 gene in WDL/DDLs (136/146, 93.2%) and low-grade osteosarcoma (21/22, 95%), slightly lower than that of MDM2 (100%). This evidence concerns the gene MDM2 and osteosarcoma.