Designer siRNAs to overcome the challenges from the RNAi pathway.

Small interfering RNA (siRNA)-based technology is playing a pivotal role in understanding gene function. Huge siRNA libraries coupled to high-content screening are being applied to decipher molecular circuitries, as well as to identify novel therapeutic targets. Further, the technology is finding its way towards therapeutic applications. In the midst of all this excitement, the siRNA technology is faced with challenges, arising mostly from siRNAs being a nucleic acid molecule, and also from the baggage it inherits from the RNA interference (RNAi) pathway, which is critical to the function of siRNAs.