IntroductionIn the 19th century, Rudolf Virchow observed the presence of leukocytes in tumor tissues. This observation established the first possible link between inflammation and cancer. Over the past two decades, our understanding of inflammation and cancer has supported Virchow's observations (1). Up to 15% of cancers worldwide have been associated with infections. Additionally, there is strong evidence that chronic inflammation and autoimmune reactions can increase cancer risk. (2). Inflammation can act as a cancer initiator because local inflammation enriches tissues with oxygen, nitrogen, and free radicals that kill pathogens and can directly cause DNA damage and DNA mutations ( 3). The immune system has the ability to repair damaged tissues. , by releasing cytokines, chemokines, and growth factors, these agents can directly or indirectly stimulate tumor cell proliferation (4). Inflammatory cells also appear to play a crucial role in vessel formation, can provide tumors with necessary components, and play an important role in metastasis (3). However, the inflammatory process can also contribute to the elimination of tumor cells. Tumor cells produce antigens that can be recognized either by specific immunity or by innate immunity via natural killer (NK) cells (5). These statements explain the extraordinary importance of inflammation and how it can act as a double-edged sword: under specific conditions. If stimulated, they can produce factors and free radicals capable of directly destroying tumor cells. However, it appears that some tumors can use inflammatory responses for their own benefit to grow and move throughout the body. Objective and methods It is clear that we need to deepen our knowledge of inflammation... middle of article... ...production processes do not survive, and only a small proportion can survive, a large number of animals are therefore necessary to produce transgenic mice (20).ConclusionInflammation is a multifactorial player in the development of cancer. The inflammatory process can initiate, promote or inhibit tumor progression. In vitro studies cannot provide a complete picture of the involvement of inflammation in cancer, unlike in vivo tumor models which provide the basis for screening new targets that may improve therapeutic strategies against cancer. Although in vivo transgenic tumor models are widely used, they nevertheless present serious economic and ethical concerns. Furthermore, tumor-bearing mice are not the best model for studying the anti-tumor activity of the immune system because the inflammatory infiltrate is far less massive in mouse tumors than in human tumors.. (2).