<p>miRNAs function via&nbsp;base-pairing&nbsp;with complementary sequences within&nbsp;mRNA.&nbsp;As a result, these mRNA molecules are&nbsp;silenced, by one or more of the following processes:</p>

<ul>

<li>Less efficient&nbsp;translation&nbsp;of the mRNA into proteins by&nbsp;ribosomes</li>

</ul>

<p>miRNAs resemble the&nbsp;small interfering RNAs (siRNAs)&nbsp;of the&nbsp;RNA interference (RNAi)&nbsp;pathway, except miRNAs derive from regions of RNA transcripts that fold back on themselves to form short hairpins, whereas siRNAs derive from longer regions of&nbsp;double-stranded RNA.&nbsp;The&nbsp;human genome&nbsp;may encode over 1000 miRNAs, which are abundant in many mammalian cell types&nbsp;and appear to target about 60% of the genes of humans and other mammals</p>