The most frequently characterized cytogenetic alterations in neuroblastoma include: (i) amplification of the gene encoding MYCN (a protooncogenic transcription factor), localized at 2p24; (ii) loss of heterozygosity (LOH) or rearrangements of the distal portion of 1p31-ter, 3p22, 11q23; (iii) gain of chromosome arms 1q or 17q. The gene discussed is MYCN; the disease is neuroblastoma.