Introduction

It has long been known that somatic or inherited mutations in SMARCB1, a core subunit of the SWI/SNF chromatin remodeling complex, can cause highly malignant rhabdoid tumors both in the central nervous system and elsewhere 1, 20. More recently, a high frequency of somatic mutations in various additional genes involved in chromatin modulation has been the most consistent novel finding of genome sequencing studies across many different tumor types, including sarcomas, carcinomas and hematological malignancies (eg, 2, 6, 8, 12, 15, 19, 21). This is especially true for various brain tumors, including medulloblastoma and glioblastoma—the two most common malignant brain cancers in human 3, 4, 5, 9, 10, 11, 13, 14, 16, 17, 22. At this stage, however, relatively little is known about the downstream phenotypic consequences of such mutations, especially how they influence the tumor epigenome in such a targeted way that often only a few dozens of genes display altered expression patterns. As a nice example, the profound effect that a single mutation in the IDH1 gene might have on the epigenome of high‐grade gliomas, including alterations to both DNA methylation and histone modifications, has recently been established 7, 18.

The timely mini symposium on the role of chromatin modifiers in brain tumors in this issue of Brain Pathology gives an expert summary on recent advances in the interface between genetics and epigenetics in various malignant brain tumors. It also provides an outlook on how these developments may influence patient management in the near future, including targeted therapeutic intervention and prediction of response to “epigenetic” drugs.