The shortened life span and increased tumor burden was significantly different in the Smug1−/− Ung−/− Msh2−/− mice versus Ung−/− Msh2−/− mice implying a role for SMUG1 in protecting cells from genome instability induced cancer, perhaps through direct removal of hmdU moieties Figure 5B. The gene discussed is SMUG1; the disease is neoplasm.