Figure 1: Proliferation and apoptosis in the primary tumor. In (a) the normal morphology of the foot is seen in a PBS-treated mouse (PBS). Panels (b) and (c) demonstrate at successively higher magnifications the change in the foot injected with 66cl4 cells from a mouse breast carcinoma (CA group). Mostly undifferentiated tumor tissue is found. In panel (d) PCNA-stained cells are seen in the TT-treated tumor (arrows), and the graph (e) shows no significant differences in proliferation between CA and TT groups. Apoptosis was assessed by immunohistochemistry (arrows) of the TT-treated tumor (f) and quantified in the graph (g) showing no significant differences between mice from the CA and TT groups. Bar = 250 m in (a) and (b). Bar = 50 m in (c), (d), and (f).