Small RNAs (~20-30 nucleotides in length) are found in many eukaryotes and act to guard against unwanted RNA such as viruses, transposons and mRNAs. One family of small RNAs called microRNAs regulates protein-coding mRNAs by repressing translation or inducing mRNA decay. Narry Kim discusses how microRNAs play a key role in animal development and diseases such as cancer and gives a step-by-step description of the microRNA biogenesis pathway and the points at which the pathway can be regulated.

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Part One: microRNA biogenesis and regulation

Part Two: Tailing in the regulation of microRNA and beyond

In Korean: Overview of microRNA biogenesis and regulation