Cancer treatment used to be focused on killing or removing cancer cells and tumors, with chemotherapy or surgery or radiation. These treatments can be very effective and in many cases are still used. In 2018 the Nobel Prize in Physiology or Medicine was awarded to James P. Allison and Tasuku Honjo “for their discovery of cancer therapy by inhibition of negative immune regulation.” Cancer immunotherapy attempts to stimulate the immune system to destroy tumors. A variety of strategies are in use or are undergoing research and testing. Randomized controlled studies in different cancers resulting in significant increase in survival and disease free period have been reported and its efficacy is enhanced by 20–30% when cell-based immunotherapy is combined with conventional treatment methods.