Very correct. This is just the second time that RNAi has been tried in humans [1] and delivery was always the big problem. When Merck acquired SIRNA, much of the discussion was around what were the options beyond ocular delivery and while nanoparticle-based delivery was always the leader in the clubhouse, no one really knew if it would work. So, it's good to be cautious. As Derek points out in the article that's been linked to, we don't know if the therapy itself was useful at this point.

Having said that, given how difficult it has been to get here, this is super cool.

1. http://pipeline.corante.com/archives/2010/03/25/nanoparticle...