Epigenetics is also known as pseudogenetics or postgenetics, and explores heritable changes in gene expression or cell phenotype through certain mechanisms, without changes in the DNA sequence in biology and specific genetics (1, 2). Inflammation is a basic pathological process that occurs in living tissues with a vascular system in response to the stimulation of various damage factors (3–6). It is well-known that inflammation is mediated by a variety of immune components (including complements, cytokines, chemokines, transcriptional factors, pattern recognition receptors, etc.) secreted or expressed by immune/non-immune cells (2). Mounting evidence supports that epigenetic modifications are associated with the occurrence, development, and resolution of inflammation via remodeling immune/non-immune cells and the microenvironment (5, 6), thus promoting or repressing the progression of many inflammatory diseases such as diabetes (7–9), rheumatoid arthritis (RA) (10, 11), asthma (12, 13), fatty liver diseases (14, 15), and cancer (16–18). Mechanically, inflammation can induce changes in the epigenetic landscape in an inflammatory microenvironment (6, 19), and epigenetic modifications can in turn maintain and promote the development of inflammation by regulating the expression of various immune components (20, 21). With studies on the development of epigenetic modifications in inflammation and with rapid research progress on mechanisms and drug discovery, some star targets (lysine-specific demethylases (22, 23), BRD4 (16, 17, 24), EZH2-EED protein-protein interaction (25, 26), and HDACs (27)) have been used in the diagnosis or treatment of inflammatory diseases in cellulo and in vivo. Therefore, investigating the functions of epigenetic immune components in inflammatory diseases not only helps reveal the molecular mechanism of a variety of inflammatory diseases, but also develop novel theranostical strategies against these diseases.

This Volume II Research Topic continually collected excellent works on the “Epigenetics of the Immune Component of Inflammation,” and a total of 9 articles from 77 authors were accepted, which demonstrates the great interest in this Research Topic in this field, deepens the understanding of epigenetic regulation in immune diseases and inflammation responses, and highlights the clinical significance of epigenetic regulation and inflammatory immune components in disease theranostics. This Research Topic can be roughly divided into the following three subtopics.