**3. Mechanism of action**

The mechanism of action of microRNA is such that it binds to its partial complementary sequence in the target mRNA (that codes for protein). Hence, the expression is repressed (**Figure 2**) and no product is synthesized [7].

In another scenario, the microRNA may bind to the complementary sequence of target mRNA that codes for protein and initiates RNA-mediated gene silencing, with the resultant cleavage of the target RNA (**Figure 3**) [26].

*MicroRNA: A Signature for Cancer Diagnostics DOI: http://dx.doi.org/10.5772/intechopen.90063*
