This enrichment for K27 methylation is associated with gene silencing, and genes in this group include cancer-associated genes such as p16INK4A and CDK6. Genes that were reduced for H3K27me3 marks and were transcriptionally upregulated include the glioma-promoting candidate neural restricted transcription factor OLIG2 (Chan et al. 2013), which may promote collapse of p53 signaling (Mehta et al. 2011). This evidence concerns the gene TP53 and central nervous system cancer.