Thus, the MYCN expression in the TgMYCN_TT line could be regulated at the post-transcriptional level, which might link to the increased penetrance of NB to ~70% by 29 wpf [50] in the TgMYCN_TT line as compared to ~30% in the MYCN line by 25 wpf [48]. Here, MYCN is linked to neuroblastoma.