TH and neuroblastoma: Overexpression of N-MYC initiates tumorigenesis by preventing the normal physiological process of neural crest cell death in TH-MYCN transgenic mice in which human MYCN is under the control of a tyrosine hydroxylase (TH) promoter, and the formation of neuroblastoma involves further changes of the persisting embryonal neural crest cells, including MYCN amplification (49).