Biological or Targeted Therapies Biological therapy incorporates the use of living organisms, the laboratory-produced versions of similar substances, or the substances derived from living organisms in order to treat disease. Few biological therapies for cancer utilize bacteria or vaccines to stimulate the patient’s immune system so that, it can act against cancer cells. This sort of biological therapy, that is referred as biological response modifier therapy or immunotherapy, don’t directly target cancer cells. However, other biological therapies, like segments of genetic material (RNA or DNA) or antibodies, directly target cancer cells. The Biological therapies which interfere with specific molecules involved in a tumor growth, as well as progression, are also referred as targeted therapies. For patients with cancer, the biological therapies can be used to treat cancer itself or wise the side effects of other cancer treatments. Even though many forms of biological therapy have been approved by the government so far, others remain experimental and in clinical trials. Generally, it is believed that the natural capacity of the immune system is to detect and destroy the abnormal cells that prevent the development of many tumors. But, some cancer cells can evade the detection by using few strategies. For instance, cancer cells can undergo genetic changes which lead to the loss of cancer-associated antigens, that makes them less visible to the body’s immune system. In addition, they may also utilize various mechanisms in order to suppress the immune responses. Immunotherapy can overcome these barriers to an effective anticancer immune response. As these biological therapies can counteract immunosuppressive signals produced by the cancer cells or increase or restore the activities of specific immune-system components.