Restoration of apoptotic responses and tumor regression by bortezomib. (A) Immunoblotting detecting p53ER^TAM in Mp53ER^RES cells (left) and tumors (right) treated with 4OHT or bortezomib or both. For the in vivo experiment, 2 independent tumors were included in each treatment group. (B) TUNEL staining of the same tumors. Images were captured and processed as described in Figure 2A. (C) Kinetics of tumor growth in 4OHT- or bortezomib-treated animals. Each group contained 4 mice; error bars represent SD. (D) The effects of 4OHT and bortezomib on circulation of neoplastic cells in peripheral blood following tail vein injections. Each group contained 5 mice; error bars represent SD.