In a study of the proliferative activity of breast cancers, Veronese 
and Gambacorta (AJ Clin Path, 95(1991), 30-34) used the Ki-67 
monoclonal antibody and immunohistochemical methods. The investigators 
obtained tumor tissues from 203 patients with breast carcinoma. The 
data are the Ki-67 values expressed as percentages for these patients.