Strictly speaking, targeted therapy falls under the category of biological treatment, which involves stimulating a cancer patient's natural defense mechanisms by administering specific substances to the body, thereby exerting an anti-tumor effect.
In recent years, some scholars have suggested that any substance capable of modulating the relationship between patients and tumors in a way that benefits cancer treatment can be classified as a biological response modifier. These include:

1. Cytokines
2. Immune effector cells against tumor cells
3. Monoclonal antibodies
4. Cancer Vaccine
5. Anti-angiogenic drugs
6. Enzyme inhibitors involved in signal transduction
7. Ubiquitin-Proteasome Inhibitors
8. Cell Differentiation Inducer
9. Active Compounds in Herbal Medicines
11. Other

Biological therapy is a broad concept—or rather, a therapeutic approach—whose key principle relies on harnessing the patient’s own bodily conditions and immune functions to achieve an anti-tumor effect. In contrast, this approach contrasts with the use of cytotoxic drugs to treat tumors, which is what we traditionally know as chemotherapy.