MTMR3 and systemic lupus erythematosus: While many studies have demonstrated associations of genetic variants related to miRNA genes or their target genes with the risk of RA or SLE35–37, our study has several improvements on previous studies in that it is the first to propose MTMR3 rs12537 in the miR-181a-binding site as a novel genetic marker of both RA and SLE risk and prognosis.