MYCN and neuroblastoma: When MYCN was knocked-down by RNAi in selected neuroblastoma cell lines, cyclin A1 (CCNA1, OMIM 604036) and cyclin G2 (CCNG2, OMIM 603203) were upregulated alongside the cyclin-dependent kinase inhibitor CDKN1C [45], suggesting a functional connection between MYCN amplification and cell cycle control.