Micro ribonucleic acid（miRNA） is small non-coding single-stranded RNA molecules about 21-23 nucleotides in length, which involved in various biological processes, such as cell proliferation, differentiation, apoptosis, developmental. Emerging evidence has demonstrated that miRNA played an extremely important role in the immunesystem; it is aberrantly expressed in autoimmune diseases, such as rheumatoid arthritis and systemiclupus erythematosus. And it is important regulatory factor of occurrence and development of autoimmune diseases. In this review, we review the many newly discovered roles of miRNA regulation in immune functions and the relationship between autoimmune diseases, oral precancerous lesions and miRNA.
