MicroRNAs function on a new level.

In this issue of Blood, Zardo et al describe an emerging mechanism by which microRNAs can regulate gene expression in blood cells via transcriptional gene silencing (TGS). The authors provide evidence that miR-223 binds to specific sites within the promoter of its target gene Nfia and represses transcription by influencing epigenetic events. These observations support the notion that multiple mechanisms of miRNA-mediated gene repression exist and should be considered when investigating gene targets of a given miRNA of interest.