DFFB and neoplasm: We also observed cleavage of DNA Fragmentation Factor A (DFFA) within persisters (Figure 2M), a caspase 3 target that upon cleavage releases active apoptotic DNase DNA Fragmentation Factor B (DFFB) which induces DNA damage.7 Persister DNA damage (Figures 2M–N and S2E) together with dysregulation of DNA repair genes (Figure 2O), including genes previously implicated in stress-induced mutagenesis5 (Figure S4G), may promote mutagenesis and tumor evolution.