In the late 19th century, Mendel’s pea plant experiments demonstrated that invisible genes control visible traits, and that the traits could be inherited to offspring through the transmission of a gene from a parent. A mutation may change the corresponding trait. Epigenetics was coined by Waddington in 1942, and finally, a consensus definition was made as "stably heritable phenotype resulting from changes in a chromosome without alterations in the DNA sequence".

Epigenetic mechanisms turn on/off a DNA/RNA or protein expression level, or up-/down-regulate a molecular activity, based on the “exposure” to all kinds of environmental stimulations and developmental changes. Currently, epigenetics, especially DNA methylation and protein acetylation, has been investigated widely and is becoming one of the hot research fields. For example, DNA methyltransferase 1 and 3b can polarize macrophages by methylating PPARg1 promoter, contributing to inflammation and insulin resistance. Sirt family proteins are reported to de-acetylate Nf-kB molecules and have important roles in initial response against endotoxin and the following endotoxin tolerance.

This Special Issue is open to researchers throughout the world who are interested in epigenetic fields of immunity, including basic and clinical research, innovative applications, and therapeutic challenges. Contributions in terms of advanced reviews, methodological developments, or innovative applications of epigenetics in immunology are all welcome. We aim to publish high-quality research papers that employ a variety of rigorous methods, strong empirical evidence, and extensive numerical results.

Potential topics include but are not limited to the following:

• Methylation or de-methylation of DNA or RNA, which can regulate the transcriptional ability of a promoter or coding sequence
• Protein post-translational modifications (including acetylation, methylation, phosphorylation, ubiquitination, sumoylation, ribosylation, and citrullination), which can alter protein function at a translational level without sequence change
• Noncoding RNAs, which are from transcribed DNA but not translated into protein, that function as a regulator at transcriptional and post-transcriptional levels