miR-21 alters circulating Treg function in vascular disease—hope for restoring immunoregulatory responses in atherosclerosis?

The small molecule regulators of gene expression, microRNAs, have emerged as important mediators in a variety of cellular processes linked to disease. Much emphasis has been placed on measuring the expression of these molecules as novel biomarkers of disease. In particular, miRNA profiles of cancer have revealed both tumor specific signatures as well as highlighting common miRNAs with central roles in malignancy. Chief amongst these is microRNA-21, miR-21, the expression of which is enhanced in multiple solid tumors and lymphomas (1) where it regulates transformation by limiting the expression of various tumor suppressor genes (2).