Oncolytic Adenovirus: Getting There Is Half the Battle

In recent years, there has been intense research into retar- geting Adenovirus (Ad) for applications in gene therapy. The goal is to ablate the natural tropism of the virus, while concomitantly targeting it to specific cell types [1]. However, Bernt et al. report in this issue of Molecular Therapy that retar- geting may be insufficient to rectify the significant problem of viral loss after systemic administration [2]. They found that other factors, such as virus stability in blood and translocation through the hepatic sinusoids, might also pres- ent barriers that contribute to poor transduction of target tis- sue.