Primary objective of this article is to explain benefits of Gene Therapy for Cancer. Gene therapy can be defined as a set of data and databases with which to name treatments specific to the individual’s genetic setup. So as to understand this approach, one has to have a basic understanding of exactly how cancer cells work. Cancer usually starts having a single cell. It then grows from the body by multiplying. This multiplication is done by a process termed mutation, during which it not only divides indefinitely; it also renders the immunity process powerless in stopping the item. This is because it is so just like healthy genes that the immunity process cannot distinguish between it and healthy genes.