Small molecule drugs often treat symptoms only rather than curing underlying cause of the disease. This requires frequent administration of the drugs to manage the condition. Gene therapy holds the potential to correct underlying genetic defects. Moreover, a clinically sound and successful gene therapy may only require a single dose to cure a disease rather than requiring a lifetime treatment. Commercially approved gene therapies include Kymriah (Novartis AG), Yescarta (Gilead Sciences, Inc.), L More