CASP3 and neoplasm: Furthermore, immunofluorescence staining of cleaved caspase-3 in tumor sections indicated that treatment with VNP-pN-FADD or VNP-pN-N-FADD greatly activated caspase-3 compared with VNP or VNP-pN (p < 0.01), even though both VNP and VNP-pN also significantly activated caspase-3 compared with PBS control (p < 0.05) (Fig. 6C,D).