MYCN and neuroblastoma: Because neither polySia-NCAM nor NCAM expression associated with MYCN amplification (Table 2), which is a common feature in metastatic neuroblastoma, it appears that polySia-NCAM may be an independent marker for metastatic activity in neuroblastoma, like in rhabdomyosarcoma, NSCLC and SCLC [16,18,20].