N6 -methyladenosine RNA methylation: A novel regulator of the development and function of immune cells.

N6 -methyladenosine (m6 A) RNA methylation is a reversible posttranscriptional modification in eukaryotes involving three types of functional proteins: "writers", "erasers", and "readers". m6 A regulates the metabolism of messenger RNAs and noncoding RNAs through RNA structure, splicing, stability, export, and translation, thereby participating in various physiological and pathological processes. Here, we summarize the current state of m6 A methylation researches, focusing on how these modifications modulate the fate decisions of innate and adaptive immune cells and regulate immune responses in immune-associated diseases, including viral infections and cancer. These studies showed that m6 A modifications and m6 A modifying proteins play a critical role in pathogen recognition, immune cell activation, immune cell fate decisions, and immune reactions. m6 A is a novel regulator of immune system homeostasis and activation.