MYCN is a classical oncogenic transcription factor and its aberrant expression is thought to deregulate neuroblast differentiation programmes by a variety of means, including recruitment of gene repressing components of the epigenetic machinery, such as histone deacetylases (Iraci et al., 2011) and Polycomb proteins such as EZH2 (Corvetta et al., 2013), the latter being a histone methyltransferase (HMT) independently shown to repress tumour suppressor genes in neuroblastoma (Wang et al., 2012). This evidence concerns the gene PRDM9 and neuroblastoma.