**10. Conclusion**

As many guidelines are available for selection of efficient siRNAs and they promise to improve efficacy in silencing, much progress has been made in designing siRNAs with improved targeting success rate. Now the main challenge in in-silico siRNA design is reducing the unintended effects arising from inadvertent targets. While the off-targets with near perfect sequence complementarity with the given siRNA is taken care of much efficiently by targeting against a unique region of the target mRNA, which can be found by homology searching with other mRNAs of the organism, miRNA-like off-targets remain to be addressed with efficiency. The few online siRNA designing solutions those consider for reducing such off-targets rely on reducing the number of off-targets. Even then a compromise has to be made between potency and specificity as siRNA sequences that could give higher specificity often comes with lower potency. Now approaching this specificity issue arising from miRNA-like off-targets of a siRNA from a different point of view, like the functional off-target filtering discussed in previous section, may prove to be beneficial and may emerge as a new paradigm for designing efficient siRNAs with customized specificity.
