Abstract
Setting the right target: Most researchers who use small RNAs in mammalian cells assume that mRNA will be the target. Recent studies suggest that small RNAs can also target chromosomal DNA. Few discoveries have had the impact of RNAi. Most researchers who use small RNAs to control gene expression in mammalian cells assume that mRNA will be the target. Recent studies, however, have suggested that small RNAs can also target chromosomal DNA.