CD8A and cancer: Integration deficiency of ZVex was achieved through genetic inactivation of the integrase (D64V mutation) and extended deletion of the 3′ region of the vector genome.45, 46 In mice, ZVex induced robust polyfunctional effector and memory CD8+ T cell responses with prophylactic and therapeutic effects in infectious disease and tumor challenge models after single injection.45, 65 ZVex is currently being evaluated in phase 1 and 2 cancer therapy studies in humans.