What are the pros and cons of RNA interference?

Pros: high specificity, low concentrations of dsRNA/siRNA needed, effective gene suppresion, widely applicable and therapeutic potential, siRNAs can be created exogenously and made to target specific mRNAs. cons: competition with endogenous RNAs (in case of exogenous administration), stimulation of the innate immune system, silencing of off-target genes which can create a toxic phenotype.