BIRC5 and neoplasm: In comparison with the expression levels of the Survivin and cleaved caspase-3 protein in the tumor tissues from the mice injected with the other complexes, the tumor tissues from the mice injected with RGD-PEG-g-PEI-SPION/siRNA exhibited the lowest level of the Survivin protein and the highest level of the cleaved caspase-3 protein with regard to the distribution range and intensity of protein expression.