The blood-brain barrier acts as the gate-keeper to the brain and is critical for proper neuronal function. While the barrier normally acts to protect the brain from toxins and pathogens, it is also a huge obstacle for drug delivery to effectively treat brain tumors. Dr. O’Brown studies the molecules that regulate blood-brain barrier development and function. By understanding how the barrier is normally formed and which molecules are necessary to keep the barrier intact, she can then genetically or chemically tweak these molecules to open the barrier and allow for better treatment of brain cancers.