Neuroblastoma is a pediatric cancer with significant genomic and biologic heterogeneity. p16 and ARF, two important tumor-suppressor genes on chromosome 9p21, are inactivated commonly in most cancers, but paradoxically overexpressed in neuroblastoma.
It is noted that the immunohistochemical positivity of MDM2, CDK4, and p16 do not necessarily indicatemalignant neoplasm such as dedifferentiated liposarcoma.