In order to estimate the proliferation activity of tumor cells, Ki-67 immunolabelingwas conducted (Figure 3).Tumors that received no treatment showed a Ki-67 labeling index of 23  ±  4%(mean  ±  SE), while tumors treated with FUS alone or a single dose of 8 Gy yieldeda labeling index of 15  ±  3% and 14  ±  2%, respectively. Here, MKI67 is linked to neoplasm.