Which of the following is NOT one of the six main types of immunotherapy?

Targeted therapy is a treatment approach that focuses on specific molecular targets associated with cancer. Unlike immunotherapy, which harnesses the body's immune system to fight cancer, targeted therapy usually involves the use of drugs that act on specific genes or proteins that are involved in the growth and survival of cancer cells. Therefore, it does not fall under the umbrella of immunotherapy, which includes strategies designed to stimulate or enhance the immune response against tumors.

The main types of immunotherapy typically include adoptive cell therapy, nonspecific immunotherapies, and oncolytic virus therapy. These methods are all rooted in enhancing the immune response directly against cancerous cells or by creating a hostile environment for tumor growth. By understanding the distinctions between these categories, particularly that targeted therapy is primarily focused on the cancer cells themselves rather than leveraging the immune system, one can appreciate the unique role immunotherapy plays in cancer treatment.