To determine the mechanism responsible for transient increase in effector function, investigation of the effect of ADT on CTL response to a well-defined immunodominant tumor antigen in non-tumor-bearing C57BL/6 mice indicated that the enhanced the proportion of antigen-specific CD8+ T cells in the spleen following ADT declined by 5 weeks accompanied with an increased proportion of Tregs in the ADT and immunized animals. The gene discussed is CD8A; the disease is neoplasm.