This study showed that anti-CXCR4 scFvs induced the expression of the pro-apoptotic proteins Bax, p-p53, c-caspase-8, c-caspase-3, and c-PARP-1 and decreased the expression of Bcl-2 and pro-caspase-9 in all three cancer cell lines compared to the two negative control antibodies (Figures 5–7). This evidence concerns the gene PARP1 and cancer.