Chromosomal and molecular abnormalities have been identified in patients with neuroblastoma. These markers are used to assess prognosis and have been included into the strategies used for a risk group staging system - see below. The most important of these is the oncogene MYCN. Amplification of the MYC family member (MYCN) is found in about 25% of cases and correlates with high-risk disease and poor prognosis. MYCN is the most established genetic marker of risk in neuroblastoma