Significantly, BS/U6/lamin A/C siRNA had no effect on the expression level of the related lamin B gene (FIG. 2, compare m with j), demonstrating that the observed RNAi effect is gene-specific. [0199] Having demonstrated that the DNA vector-based RNAi worked well to inhibit the expression of the lamin A/C gene, we asked whether this strategy functioned broadly to inhibit genes of interest by examin