Demonstration of the suppressive effects of IFN-γ on cancer cell growth both in vitro and in vivo has been unequivocal [37-39] and the production of IFN-γ in response to chemotherapy is one marker used to assess the success or failure of treatment in vivo; it is considered an indicator of immune activation and anti-tumor activity [40,41]. The gene discussed is IFNG; the disease is neoplasm.