Introduction

In the realm of genetics, the discovery of DNA and its double helix structure led to the assumption that genetic sequences alone determine cell phenotypes. However, researchers began to observe cases where organisms with identical genetic information exhibited different traits. This realization gave birth to the field of epigenetics, which explores the reversible influence on gene expression without altering DNA sequences. Epigenetic mechanisms encompass DNA methylation, histone modification, chromatin remodeling, and the effects of noncoding RNA. These processes involve “writers,” “readers,” and “erasers” that add, recognize, or remove chemical groups from DNA or histones. The cooperation between the epigenome, transcription factors, noncoding RNAs, and external stimuli regulates gene expression in a temporary yet long-lasting manner. Understanding normal and abnormal epigenetic processes is crucial for comprehending diseases like cancer and developing potential treatments.