Influences gene expression through chemical modifications that do not alter DNA sequence.
Epigenetic changes, such as DNA methylation and histone modifications, represent a heritable layer of information that regulates DNA transcription. In many organisms, these changes are essential for understanding gene regulation and expression. Epigenetic dysregulation, such as the methylation of DNA (CpG), modifications of histones, binding of microRNAs to block translation, post-transcriptional silencing by short interfering RNA (siRNA), and modification of chromatin structure by noncoding RNA (ncRNA), are associated with several diseases, including cancer. Epigenetics studies can unveil variations in expressed phenotypes, X-chromosome inactivation and transcription errors.