Percent Change in Tumor Volume (IMAGE) University of Chicago Medical Center Caption Tumor cells in the placebo-treated mice grew rapidly. Tamoxifen prevented the tumors from growing. CDB4124 initially caused the tumors to regress, but after 35 days, the tumors began growing again. The combination of tamoxifen and CDB4124 caused tumors to shrink 70 percent by day 60. Credit The Greene Laboratory Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.