This video describes the immunoglobulin G antibody and its role in the immune response. The structure of the antibody and the importance of its associated carbohydrates are described in detail. Binding of immunoglobulin G to membrane-bound receptors on the surface of immune cells such as B cells, macrophages and natural killer cells leads to initiation or inhibition of an immune response. This process is critical to protect us against infection and cancer through biological processes such as antibody-dependent cellular cytoxicity. Also discussed is how the biopharmaceutical industry is now exploiting antibodies and their properties to provide new treatment options for various diseases. These therapeutic monoclonal antibodies exploit the body’s own immune system in so-called immunotherapy.