The MYCN (MYCN proto-oncogene, bHLH transcription factor, a.k.a. NMYC) gene is located in the chromosomal region 2p24.3 and encodes a 62-64 kDa transcription factor mainly expressed in the developing nervous system. Amplification of the MYCN gene is found in about 25% of primary neuroblastomas and is strongly associated with rapid tumor progression, advanced stages of the disease, and poor prognosis. Neuroblastoma (NBL) is an embryonal cancer of the sympathetic nervous system (SNS), which causes 15% of pediatric cancer deaths. Hence, amplification status is increasingly being used for stratification of patients to different treatment protocols.

MYCN amplification represents the most powerful unfavorable prognostic factor for neuroblastoma. Less frequently amplifications are found in retinoblastoma, small cell lung cancer, astrocytoma and other tumors derived from the neuroectoderm.