Because increased activity of MYCN in stage 4s-NA or c-MYC in stage 4-NA tumors should both result in high expression of shared target genes compared to localized-NA neuroblastomas, we analyzed known direct MYCN/c-MYC target genes, namely MDM2 [21], DKC1 [22], and PTMA [23], in neuroblastoma subtypes. Here, MYCN is linked to neuroblastoma.