**7. miRNA therapeutics in disease**

miRNAs are abundant in many mammalian cell types and appear to target about 60% of the genes of humans and other mammals [54]. Many miRNAs are evolutionarily conserved, which implies that they have important biological functions. However, growing evidence suggests that alteration of miRNAs expressions plays a key role in the development of disease. The signature miRNAs associated with disease and their potential therapeutics in the most common diseases are discussed in the following sections.
