Immunotherapy is treatment that uses a person's own immune system to fight cancer.Immunotherapy is a type of cancer treatment that boosts the body's natural system of fighting against cancer. Cancer immunotherapy, also known as immuno-oncology, is a form of cancer treatment that uses the power of the body's own immune system. Immunotherapy enables the immune system to recognize and target cancer cells, making it a universal answer to cancer. cancer cells have multiple ways to evade, shut down or overpower an immune attack. Immunotherapy is a broad category of cancer therapies designed to fight against cancer. Tumor necrosis is often limited to a small area within the sample. Its presence suggests a more aggressive breast cancer. Hypoxia is a marker of more aggressive tumors and tumor necrosis was significantly associated with features such as high histologic grade, vascular invasion by tumor cells and reduced survival. Interleukin 2 (IL-2) is naturally produced by the body to help fight infection and prevent autoimmune diseases. In cancer treatment, IL-2 is designed to target adaptive immune cells, such as T-cells and B-cells, to respond to tumors. IL-2 may help the body produce antigen-fighting T-cells and stimulate B-cells to produce more antibodies. Interferon-alpha (IFN-alpha) is one of several proteins that help the body fend off viruses and bacteria. In cancer treatment, IFN-alpha helps the body generate innate immune cells, such as dendritic cells and macrophages, that are designed to attack unhealthy cells. Immunotherapy may cause immune cells to attack healthy cells, which cause a variety of side effects, including fatigue, nausea, diarrhea, and flu-like symptoms.