CASP3 and neoplasm: Finally, we analyzed E0771 tumor sections to assess whether BMP9 affected tumor cell proliferation and apoptosis, in vivo, by counting the number of PCNA-, cleaved caspase 3- and TUNEL-positive cells and found no significant differences between WT and Gdf2−/− mice (Fig. 1d, e, f, g, h and i).