RECQL4 and osteosarcoma: Although the exact aetiology of osteosarcoma is unknown, there is evidence that hereditary diseases such as hereditary retinoblastoma, Li-Fraumeni syndrome, Rothmund-Thomson syndrome and Werner syndrome may affect the occurrence of osteosarcoma, and the disease-causing genes of these syndromes are RB1, TP53, RECQL4 and WRN, suggesting that abnormalities in these genes may form part of the pathogenesis of osteosarcoma [18, 28].