Monoclonal antibodies used in immunotherapy are produced artificially from a cell clone therefore consist of a single type of immunoglobulin. They are targeted towards specific antigens and bind to the antigens to form a complex. The complex can be recognized and destroyed by phagocytes or used for other diagnostic purposes. CD30 has been identified as a marker on Reed–Sternberg cells in Hodgkin lymphoma and cells in other specific types of lymphoma. CD30 monoclonal antibodies may be used to treat Hodgkin's lymphoma or anaplastic large cell lymphoma.