But there are no limits to what can be considered. Most of the gene therapies that have been done to date have been like fireworks that fizzle and don't go off. There has been a lot of hype and too-high expectations, and people have been disappointed when they haven't worked the first time around. The problem is that currently we cannot effectively deliver the genes to the target, and even when we can, their expression tends to switch off too quickly. Most of these systems use viruses to carry genes into cells.
Viruses are very good at infecting cells.
Mayo is testing some gene therapies that have been developed by drug companies. But we have not developed any unique gene therapies of our own. That is about to change. There is no shortage of people here who understand diseases, have good disease models in which to study the diseases, and have potential therapeutic genes to try out. They just didn't have ways to deliver these genes.