Proliferative activity in human breast cancer: Ki-67 automated evaluation and the influence of different Ki-67 equivalent antibodies by Gasperetti F, Ferro A, Cuorvo LV, Morelli L, Bragantini E, Aldovini D, Bazzanella I, Eccher C, Cantaloni C, Leonardi E, Fasanella S, Berlanda G, Dalla Palma P, Barbareschi M