Compared with MABs, CARs have the following advantages: (1) MABs can fail to recognize tumor cells when they express too little antigen, while CARs can overcome this dilemma; (2) immune cells loaded with CARs can not only kill tumor cells directly but also secrete cytokines, such as IFN-γ and IL-2, exerting powerful antitumor effects; (3) immune cells loaded with CARs can proliferate massively and exert long-lasting anti-tumor effects after infusion [13,15,16,17]. This evidence concerns the gene IL2 and neoplasm.