Intermediate-risk neuroblastomas include stage L2 in children younger than 18 months without MYCN amplification but with 11q aberration; stage L2 in patients older than 18 months with ganglioneuroblastoma, nodular, or neuroblastoma with differentiating histology and 11q aberration; stage L2 in patients older than 18 months with ganglioneuroblastoma, nodular, or poorly differentiated or undifferentiated neuroblastoma; stage M in children younger than 12 months with diploidy; and stage M in children 12 months to 18 months old with diploidy. This evidence concerns the gene MYCN and ganglioneuroblastoma.