The mechanism of tumor formation is considered to be associated with immune abnormalities.Recently, most scholars believe that the development of malignancy is closely related to an abnormal immunological mechanism.Despite the existence of an autoimmune mechanism against tumor development, it is difficult for the immune system to kill tumor cells at a later stage if most of the tumors have escaped from the system during the initial stage of development.In recent years, researchers continue to find some small molecules with anti-tumor effect, including small molecule polypeptides, or a small molecule compound, for example, imatinib, gefitinib, thalidomide, all-trans retinoic acid, arsenious acid and so on.