CASP3 and neoplasm: Immunostaining of post-treatment tumor tissue with anti-CD31 antibody to visualize tumor vasculature showed that compared to controls PL3-D(KLAKLAK)2-NW-treated tumors had a significant reduction in CD31-positive area and cleaved Caspase-3 showed a significant increase in apoptotic cells (Figs. 6D, S12, S15).