The INRG classifier includes age of a patient at diagnosis (children of ≥18 months of age have poor prognoses), INGRSS stage, histologic category, grade of differentiation, MYCN status (amplification of the MYCN oncogene is diagnosed in about 20% of NB patients), ploidy, and the presence or absence of gain in the long arm of chromosome 11. Here, MYCN is linked to neuroblastoma.