The IHC analysis of DU145 tumor samples showed that flavonolignans treatment significantly inhibits the immunostaining for PCNA (a biomarker for cell proliferation) (Fig. 1B), but increases the TUNEL and cleaved-caspase 3 positive cells (biomarkers for apoptosis) (Fig. 1C and 1D). Here, CASP3 is linked to neoplasm.