Figure 1.

DNA methylation, histone posttranslational modifications (HPTMs), and microRNA regulation include epigenetic processes. HPTMs and DNA methylation govern pre-transcription initiation gene expression. Both mechanisms restructure the chromatin framework, making genes more or less responsive to transcription factors depending on epigenetic changes. In contrast to DNA methylation and HPTMs, miRNAs regulate gene expression post-transcriptionally. By binding to mRNAs, miRNAs negatively regulate genes by destroying or repressing translation.