Monoclonal Antibodies Antibodies are proteins made by the body's own natural immune system.
Antibodies attack foreign and infectious agents called antigens.
Monoclonal antibodies are antibodies engineered through biotechnology instead of being produced naturally. They imitate immune system antibodies by providing specific actions against cancer cells. Trastuzumab is a monoclonal antibody that attaches itself to HER2 protein receptors on the surface of cancer cells. When there is an overexpression or abundance of these receptors, it is easier for trastuzumab to find targets. By binding to the HER2 proteins on the surface of these cancer cells, trastuzumab is able to slow their growth and reduce the spread of tumors.