Trimethylated fourth and twenty-seventh lysine residues on histone protein H3 (H3K4me3, H3K27me3) exert the opposing influences of gene activation and repression on the promoters of oncogenes MYCN and ARID1B. A switch in the histone code from the repressive H3K27me3 mark to the activated H3K4me3 mark has been noted on the promoters of MYCN and ARID3B in high risk neuroblastoma [6]. Here, MYCN is linked to neuroblastoma.