In the mid-1980s, Rosenberg et al. established the theory and foundation of modern biological therapy for tumors. To date, biologic therapy has become the 4th modality in comprehensive tumor treatment. Currently, tumor biotherapy mainly includes: successive cellular immunotherapy and cytokine therapy, tumor vaccine and dendritic cells, tumor molecular targeting therapy, radioimmune targeting therapy, tumor gene therapy and biochemotherapy, etc. Relay cell immunotherapy and cytokine therapy Relay cell immunotherapy is to obtain patients’ own immune cells by isolation, and under the induction of cytokines, a large number of immune effector cells with high anti-tumor activity are expanded and then infused back to patients to directly kill tumor cells or correct the low cellular immune function of the body to achieve the purpose of tumor treatment. Such cells include lymphokine-activated killer cells (LAK cells), tumor infiltrating lymphocytes (TIL cells), cytokine-induced killer cells (CIK cells), dendritic cells (DCs) and CD3 antibody-activated killer cells (CD3AK cells), etc. This therapy has good efficacy on malignant melanoma, kidney cancer, non-Hodgkin’s lymphoma and other tumors and cancerous thoracic ascites. This therapy has good efficacy on malignant melanoma, kidney cancer, non-Hodgkin’s lymphoma and other tumors and cancerous thoracic ascites, and has mild toxic side effects. Cytokines are small peptide active molecules synthesized and secreted by activated immune cells or mesenchymal cells, which have the functions of regulating cell growth and differentiation, regulating immune response, participating in inflammation response, promoting or inhibiting tumor growth. It mainly includes interferon, interleukin, hematopoietic stimulating factor, tumor necrosis factor, etc. They are used for the treatment of leukemia, lymphoma, solid tumors, viral infections, hematopoietic suppression, radiation injury, etc. Relay cellular immunity and cytokine therapy are often complementary and take a more combined application. For example, CIK/IL-2 combination, TIL/IL-2 combination, LAK/IL-2 combination, DC/IL-2/IFN-γ combination, IL-2/IFN-α/TFN-α combination, etc. can be used especially for hematopoietic stem cell directed differentiation and expansion. At present, these therapies have been clinically applied for many years and have achieved good efficacy. 2.Tumor vaccines and DCs DCs are the most effective antigen-presenting cells in human body. In recent years, research on the ideal source of DCs, specific antigens and loading methods has made great progress, and there is increasing evidence that cellular immunity activated by DCs, especially cytotoxic T lymphocyte (CTL)-mediated immune response, plays a very important role in the body’s defense against malignant tumors and infectious diseases. DC vaccines are prepared by direct stimulation of DCs with tumor antigen peptides or proteins, using tumor tissue protein extracts to stimulate DE, antigen and cytokine gene transfection of DCs, etc. The clinical phase II and III trials of DC vaccine have achieved encouraging results. 3.Molecular targeted therapy There are two main classes of molecular targeted therapy drugs: monoclonal antibodies and small molecule compounds of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI). The monoclonal antibody class of molecular targeted drugs commonly used are trastuzumab, rituximab, cetuximab and bevacizumab; the small molecule compounds commonly used are Glivec, Iressa, Tarceva, etc. The implementation of molecular targeted therapy first requires the search for the correct molecular target through techniques such as immunohistochemistry and fluorescence in situ hybridization, and the screening of suitable targeted drugs according to their results, which can be treated by simple biotherapy, biochemotherapy, bioradiotherapy, etc. Evaluate the efficacy by PET/CT, CT, MRI and tumor markers after completing a certain course of treatment and medication, pay attention to dose reduction and maintenance during the treatment process, and follow up closely. 4.Gene therapy uses cell engineering technology to introduce exogenous target genes into human target cells or tissues to replace defective genes and to achieve the purpose of tumor prevention and treatment through their normal expression. The basic strategies of tumor gene therapy include gene replacement, gene modification, gene addition, gene supplementation and gene closure. According to the different ways of functional gene introduction, there are in vivo gene therapy and in vitro gene therapy. Viruses are commonly used as vectors for gene delivery. Currently, gene transfer P53 (such as AV-P53), gene transfer DC (such as AAV-BA46-DE), gene transfer TIL (IL-2 and TNF-α), etc. are used in various phases of clinical studies, and the efficacy is subject to further clinical evaluation. 5.Biological chemotherapy Biological therapy is based on modern molecular biology, cell biology and molecular immunology and other frontier sciences, emphasizing the molecular basis of tumor development and regression and the targeting, targeting and effectiveness of treatment. It has definite efficacy when applied alone, and may be enhanced by simultaneous or sequential application with other therapies; it has no negative impact and obvious toxicity on normal hematopoietic, immune and major organ functions. Tumor biochemotherapy is a new integrated treatment mode of biological therapy and chemotherapy combined in tumor treatment, which is based on the pathological type, clinical stage, site of occurrence and development trend of tumor, combined with the patient’s systemic condition and molecular biological behavior, to systematically combine chemotherapeutic drugs and biological agents for treatment in order to achieve the best therapeutic effect. Some successful biochemotherapy regimens have been applied in clinical practice, such as Iressa+GEM for non-small cell lung cancer, Rituximab+CHOP for CD20-positive B-cell non-Hodgkin’s lymphoma, Herceptin+TAX/NVB for Her-2 positive breast cancer, and IMC-C225+CPT-1 1 for colorectal cancer, which These regimens have achieved good therapeutic effects. 6.Efficacy evaluation of biological therapy With the emergence of biological chemotherapy based on targeted therapy and immunotherapy, the traditional criteria for evaluating the efficacy of tumor treatment are facing more and more problems.King et al. proposed that in the process of targeted therapy and immunotherapy, even though the volume of tumor showed an increase on the traditional CT or MRI evaluation. It does not indicate that the targeted therapy and immunotherapy are ineffective. Di et al. found that tumor treatment started to show changes in SUV values 4 weeks after the start of tumor treatment, while changes in tumor size on conventional imaging appeared only after 8-10 weeks. The efficacy evaluation based on the change in SUV values on PET/CT has a better predictive value than the evaluation of efficacy based on the change in tumor diameter according to RECIST criteria.