Immunotherapy for lung cancer. Conceptual illustration showing monoclonal antibodies (blue) targeting a tumour in lung tissue during immunotherapy. Immunotherapy is a type of cancer treatment designed to boost the body's immune system to fight the cancer. It uses antibodies and other chemicals either made by the body or in a laboratory to restore, enhance or target immune system function. The cancerous cells are analysed, and therapy can be adapted using monoclonal antibodies. These proteins specifically target the cancer cells' receptors, and trigger an immune reaction which destroys the detected cells.