Functional relevance of miRNA sequences in human disease.

MicroRNA (miRNA) processing in the cytoplasm produces a miRNA duplex containing the forward, miRNA strand and the reverse, miRNA strand, which was thought to be degraded. However, recent evidence is challenging this dogma that miRNA is simply a non-functional byproduct of miRNA biogenesis. We present a comprehensive review of evidence that miRNA plays a significant role in cellular function and assembled a table outlining all of the publications before September 2011 that have reported on miRNA activity in human disease. Furthermore, we will present unexpected diagnostic and therapeutic implications due to the active miRNA status.