Mammalian cells, like Chinese Hamster Ovary (CHO) cells, are essential for producing complex medicines such as monoclonal antibodies. However, these cells cannot make certain compounds they need to grow, so we must add them to the culture--a process that is expensive, complex, and limits production efficiency. This project, Mammalian Metabolic Atavism (MaMA), aims to “teach” CHO cells to make these compounds again, restoring capabilities lost millions of years ago. By combining genetic engineering, computational modeling, and industrial testing, we will create CHO cell lines that grow efficiently with simpler media, produce high-quality therapeutic proteins, and reduce manufacturing costs. Beyond cost savings, this work will reveal how mammalian cells adapt to regained metabolic functions and establish a blueprint for designing more robust, self-sufficient production cells for a wide range of biologic medicines.