TREX1 and neoplasm: In sharp contrast, the inactivity of TREX1 exonuclease in the TREX1 D18N mice resulted in a dramatically reduced tumor volume that was always ~10-fold less than WT and an equally dramatic increase in median survival that was extended from 13 to 78 days in long-term survival studies, with ~40% of animals cured of their tumor for at least 120 days (Figure 3B).