MKI67 and neoplasm: Pretreatment with the reference drug amifostine at a dose of 200 mg/kg before exposure to radiation at 4 Gy resulted in an increase in the number of proliferative cells to 94 ± 35.34 and 135 ± 11.67 in the intestine and lungs, respectively, as seen by an elevation in Ki-67-stained cells, but not in the tumor tissues, which had a mean expression level of 19 ± 8.83.