By contrast, AEP deficiency, even in the absence of external genotoxic insults, resulted in an increase in γH2AX compared to control cells, but not in cleaved caspase 3 levels, reflecting a lack of induction of apoptosis (Fig. 1L, middle and right panels and quantitation), and further reinforcing the role of AEP in genomic stability in BC cells. Here, CASP3 is linked to breast cancer.