Lactation (IMAGE) University of California - Santa Cruz Caption Milk-producing alveolar cells shown in magenta and milk protein shown in yellow in this cross-section of a mouse mammary gland at day five of lactation. Credit Image courtesy of Julien Menendez, UC Santa Cruz Usage Restrictions Credit must accompany any reuse of this image. License Original 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.