Gene therapy is an advanced technique which involves the insertion of the gene in order to treat various chronic diseases such as cancer or gene mutations. Gene therapy can treat genetic defects. According to the National Center for Advancing Translational Sciences, although around 7,000 rare diseases are identified, only a few hundred have approved treatments. Moreover, gene therapy for rare diseases is gaining significant traction, as more than 80% of rare diseases have a known monogenic (single-gene) cause. Drugs which have small molecule only treat the symptom rather than curing the cause of disease which requires continuous administration of the drugs for managing the condition. Additionally, a clinically proven and successful gene therapy require only a single dose to cure disease to treat the disease. Some of the commercially available gene therapies are Luxturna (Spark Therapeutics), Kymriah (Novartis AG), Yescarta (Gilead Sciences, Inc.), and Strimvelis (Orchard Therapeutics).