1 Cancer immunotherapy Cancer immunotherapy is a way of treating cancer by improving,restoring,or activating the patient’s natural immune system to attack cancer cells using different agents.Therapies aim to reduce using offtarget cancer treatments such as chemotherapy that kills cells indifferently.With the field rapidly advancing,the more and more immunotherapy drugs are being developed and approved by the FDA.For example,one of the first approved drugs is the recombinant versions of the cytokine interferon-αin treating hairy cell leukemia.More recently,the CAR(chimeric antigen receptor)for the CD19 B lymphocyte molecules has been approved for treating refractory pre-B cell acute lymphoblastic leukemia.Nowadays,there are more than 12 immunotherapies approved and available for treatment and even more in clinical trials.