Brainshuttle is a technology that we have developed at Roche to increase penetration of large molecules such as antibodies into the brain. Access of large molecules to the brain is restricted by the blood brain barrier (BBB), a gatekeeper between the blood and the brain tissue that carefully filters which molecules can enter the brain. By using the Roche antibody engineering platform, we have created antibodies that are able to cross the blood brain barrier by binding to one of the protein receptors located on its surface. The so-called “brainshuttle” technology could potentially transport all types of therapeutic molecules into the brain, regardless of their intrinsic ability to cross the blood brain barrier.