MDM2 and osteosarcoma: Low-grade central osteosarcoma and parosteal osteosarcoma, two subtypes known to harbor amplifications of the MDM2 gene in 25–30% and >80% of cases14, respectively, displayed a limited amount of CNV: 3.62% (range: 0.03–17.50%; n = 15) for low-grade central osteosarcoma and 9.72% (range: 0.03–32.45%; n = 22) for parosteal osteosarcoma, respectively.