Epigenetics refers to the study of changes in gene expression and cellular phenotype that do not involve changes to the underlying DNA sequence. In other words, it focuses on how environmental and other external factors can modify gene expression by turning genes on or off. Epigenetics is an important area of research in genetics, as it holds potential for understanding the role of environmental exposure and other influences on disease and developmental processes. However, it also requires specialized skills in a variety of fields, including molecular biology, bioinformatics, and statistics.