MKI67 and neoplasm: The number of cells/mm2 positive for the marker of apoptosis, cleaved caspase 3, was significantly higher in the tumors of the exercising animals (t = 3.131, p = 0,0110, Figure 3D), whereas the number of tumor cells positive for the proliferation marker ki67/mm2 was similar between the two groups (p = 0.434, Figure 3E).