It would be great if we could use retroviral-like vehicles to precisely target positions in DNA. Think of the possibilities that would open up. It would be a wonderful tool for gene therapy, including cancer treatment, treatment for genetically inherited diseases, anti-viral therapy, genetic engineering, and pure research. That is why retroviral integration has been studied so carefully. Unfortunately, integrase, the enzyme that actually does the integration of a new DNA sequence into the DNA of the host organism, does not target specific loci. Update: Since the writing of the preceding, CRISPR interference has begun to become a powerful "gene editing" tool which has enormous possibilities because it can manipulate DNA in a very precise manner. Of course, CRISPR gene editing does not use retroviral-native integrases.