Immune system regulation is so complex that immunotherapeutics often can be judged only on the basis of whether or not they work in patients.

AltaRex Corp.'s Anti-idiotype Induction Therapy (AIT), for example, is not actually an anti-idiotype antibody; it is a mouse monoclonal antibody designed to induce the production of anti-idiotype antibodies. But in fact, the company notes that its true mechanism of action may be antigen presentation, not the induction of anti-idiotype antibodies.