However, no recurrent fusion has ever been found in human osteosarcoma, although osteosarcoma is known to exhibit frequent numerical and structural chromosomal aberrations, such as TP53 mutations and deletions, MDM2 amplification, CDKN2A deletion, and hemi- or homozygous loss of RB1 [5,11,12]. The gene discussed is MDM2; the disease is osteosarcoma.