Targeted systemic gene therapy and molecular imaging of cancer contribution of the vascular-targeted AAVP vector.. PubMed. Hajitou, Amin. 2010-01-01. Gene therapy and molecular-genetic imaging have faced a major problem: the lack of an efficient systemic gene delivery vector. Unquestionably, eukaryotic viruses have been the vectors of choice for gene delivery to mammalian cells; however, they