Genetics refers to the study of hereditary changes in gene phenotype or function due to changes in DNA sequence. Such alterations include point mutation, deletion, insertion, and translocation. In contrast, epigenetics is the study of heritable changes in gene activity or function with no change in DNA sequence [1]. In the early twentieth century, many scientists believed that the differentiation of progenitor cells into different somatic cells was due to an increase or decrease in their genomic DNA. However, Conrad Hal Waddington argued that the entire set of genomic DNA of a progenitor cell remains unchanged during this process and that all the changes is the differential regulation and expression of cells between different types. These changes are a response to the environment in which the organism finds itself. To explain the relationship between the intrinsic genes of a species and its environment, Conrad Hal Waddington was the first to introduce the concept of epigenetics [2–5]. After years of in-depth research, the understanding of gene regulation in eukaryotic cells continues to deepen, and the connotation of epigenetics continues to be updated. Epigenetics now focuses on the study of heritable changes in gene function during mitosis and meiosis that cannot be explained by changes in DNA sequence [1]. Epigenetic mechanisms mediate diverse gene expression profiles in a variety of cells and tissues in multicellular organisms and can regulate a wide range of complex phenotypes. Current epigenetic research is focused on three main directions: DNA methylation, histone modification, and chromatin remodeling [6–9].