MKI67 and neoplasm: Specific criteria were established for number of cells counted (definite nuclear immunoreactivity in 2000 invasive neoplastic cells in randomly selected high-power (×400) fields at the periphery of the tumor), and the Ki-67 cutoff point of 11% was established based on the median value of Ki-67 in the frequency distributions of the Ki-67 labeling index in the trial cohort.