A study released by a collaborative effort between the Comparitive Oncology Trials Consortium and the National Cancer Institute specifically targets multiple tumor types in dogs by delivering a TNF alpha gene specifically to tumor blood vessels. TNF alpha gene expression and protein production targets the tumor blood vessels for degredation, thereby inhbiting tumor growth. This trial worked pretty well in dogs. Canines were used because their cancer more accurately mimics cancer seen in human beings. The gene was delivered (targeted) to tumor blood vessels using a re-engineered bacteriophage. Mammalian cell targeting is often done with an engineered virus that is a typical human pathogen (with specific cell type for infection). I thought the use of a bacteriophage was a pretty novel idea.