Which of the following is the most common gene delivery system for 'In-vivo' gene therapy?

Adenovirus in gene therapy: ds DNA virus Replication deficient Used in In Vivo approach gene therapy As vaccines, For cancer therapy Advantages: Remain as an episome (extrachromosomal DNA) So doesn't integrate into the genome. (no chance of inseional mutagenesis) The maximum size of the inse by the adenoviral vector is 36 kb.