Checkpoint-modulating immunotherapies in tumor treatment: Targets, drugs, and mechanisms.

Tumor immunotherapy, as a new treatment of cancer, has been developing on the basis of tumor immunology. Tumor immunotherapy stimulates and enhances the function of immune system in human bodies, in order to control and kill tumor cells. It is often used as an adjuvant therapy combined with surgery, chemotherapy, radiotherapy and other conventional methods. Cancer immunotherapies involve cells, antibodies and cytokines, etc. Some immunotherapies are widely used to activate the immune system, while some others precisely target at different tumor antigens. With the development of tumor immunotherapy, immune regulation activities of small molecules and biological agents have been gradually becoming a hot research area these years. In this review, we summarize the therapeutic targets, drugs, biologics, and their mechanisms in tumor immunotherapies.