neuroblastoma with distant metastases (equal to INSS stage 4 tumors) have an unfavorable prognosis despite MYCN amplification status, whereas patients with polySia-NCAM-positive neuroblastomas (similar to INSS stage 2B-4 tumors) have a more favorable prognosis, especially when the MYCN copy number is normal. Here, MYCN is linked to neuroblastoma.