A-to-I RNA editing of miRNA precursors in human tissues. The extent of A-to-I editing at each editing site is indicated by the color scale. Each colored box represents the average extent of editing calculated from at least two PCR product sequences, at least one of which was sequenced in both directions. Gray boxes indicate miRNAs that could not be amplified. The number in brackets after the miRNA name is the position of the edited adenosine from the 5' end of the pre-miRNA or equivalent antisense pre-miRNA from the miRNA registry.