Cardiac dissonance without conductors: how dicer depletion provokes chaos in the heart.

Dicer was initially identified as the protein responsible for processing double-stranded RNA into small interference RNAs.1 Later, it was shown that on interaction with cofactors,2 Dicer also produces other kinds of small RNAs, ie, microRNAs (miRNAs).3 MiRNAs are endogenous small ribonucleotides that act as negative regulators of target messenger RNAs. It has been estimated that the human genome encodes up to 1000 miRNAs that modulate 30% to 50% of all genes, which demonstrates the importance of these small regulators as fundamental orchestrators of the genome.