CASP3 and neoplasm: To correlate the level of the therapeutic response with the induction of apoptosis, we stained tumor slices from treated mice for the presence of phosphorylated γH2A.X(Ser139) foci, a surrogate marker of DSBs, cleaved phosphorylated PARP (Asp214) foci, and cleaved Caspase 3 protein expression levels.