Cancer cells recruit immunosuppressive cells, and create a microenvironment that inhibits anti-tumor responses and enables tumor growth. Antibody-mediated blockade of immune checkpoint molecules, such as CTLA-4, PD-1/PD-L1, and indoleamine 2,3-dioxygenase (IDO), offer promising new therapeutic approaches for cancer treatment. Identification of novel targets, along with the elucidation of downstream cellular responses, is crucial for the development of new therapeutic strategies. In addition, understanding glycosylation patterns of therapeutic antibodies and how the activities of antibody-binding Fc Receptors affect antibody-mediated responses are important for researchers studying checkpoint therapeutics. R&D Systems offers a wide range of proteins, antibodies, kits and other reagents to facilitate your immune checkpoint blockade research.