MYCN and neoplasm: Notably, only two MYCN-targeting miRNAs in neuroblastoma (miR-29a-3p and miR-29c-3p) are directly downregulated upon induction of MYCN in a neuroblastoma cell line model, suggesting that downregulation of MYCN-targeting miRNAs during tumor formation is likely to result from secondary (epi)genetic events downstream of increased MYCN activity.