Breast Cells Forming Acini (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption Berkeley Lab researchers found that after five days of mitosis and CAMo, polarized breast cells assembled into an acinar sphere with a lumen in the center (inset). Credit Image courtesy of Berkeley Lab 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.