Tumor Immunology is interdisciplinary branch of biology concerned with the role of the immune system in the progression and development of cancer. The most well know application is Cancer Immune therapy whereas immune system is used to treat cancer. Cancer immunosurveillance is a theory formulated in 1957 by Burnet and Thomas, who proposed that lymphocytes acts as sentinels in recognizing and eliminating continuously arising, nascent transformed cells. Cancer immunosurveillance appears to be an important host protection process that decreases cancer rate through inhibition of carcinogenesis and maintaining of regular cellular hemostasis. It also be suggested that immunosurveillance primarily functions as a component of a more general process of cancer immunoediting.