MDM2 and neuroblastoma: The MYCN protein is a transcription factor that plays a key role in regulating the expression of many genes that promote NB progression, including, but not limited to, Ornithine Decarboxylase (ODC1), a rate-limiting enzyme in the biosynthesis of polyamines, as well as MDM2, TP53, Skp2, and PI3K/Akt/mTOR.