Previously, we and others reported that adoptive T-cell therapy using peripheral blood mononuclear cells (adoptive cell therapy, ACT), which are activated and proliferated through a culture process involving stimulation with an immobilized anti-CD-3 antibody and interleukin-2 (IL-2), has shown certain efficacy against various cancers without severe adverse events [14, 15], indicating that the efficacy of ACT might partially be derived from TILs associated with peripheral blood cells. The gene discussed is IL2; the disease is cancer.