MKI67 and carcinoma: Similarly, immunofluorescence analysis (Fig. 6d) of OE33 tumor xenografts with an antibody that recognizes carcinoma cells expressing the proliferative marker Ki-67, showed significantly lower number of carcinoma cells expressing Ki-67 per 100 total number of cells (proliferative index) in the lapatinib plus foretinib combination therapy group compared to that of the control, lapatinib or foretinib treatment groups.