: Solutions to the Overlooked Problem of Off-Targets Shared by Independent dsRNAs

often large dsRNAs are used. One of the drawbacks of RNAi technology is that unwanted gene products with sequence similarity to the gene of interest can be down regulated too. To verify the outcome of an RNAi experiment and to avoid these unwanted off-target effects, an additional non-overlapping dsRNA can be used to down-regulate the same gene. However it has never been tested whether this approach is sufficient to reduce the risk of off-targets. and we analyzed 99 randomly chosen genes.Here we show that nearly all genes contain non-overlapping internal sequences that do show overlap in a common off-target gene. findings, off-target effects should not be ignored and our presented on-line tool enables the identification of two RNA interference constructs, free of overlapping off-targets, from any gene of interest