Therapeutic siRNAs.

The ability of small-interfering RNAs (siRNAs) to silence gene expression in somatic mammalian cells has provided researchers with a novel tool to block the expression of disease-causing genes, provided that their mRNA sequences are known. siRNAs can be delivered to cells either exogenously as synthetic agents or endogenously as gene-encoding siRNAs. Recent studies demonstrate the general application of siRNAs to silence gene expression in a range of cell types and in whole mammals. Beyond their value for dissecting gene functions and target validation, siRNAs also hold great potential as gene-specific therapeutic agents.