Even in advance of the full blossoming of regenerative medicine as a field, early progress in the laboratory can still lead to viable, useful therapies. Take this, for example: "Not even the most advanced experimental techniques have been able to restore nerve function to sites far from an injury. Smith thought he might facilitate fast nerve regeneration by using lab-grown nerves as a kind of scaffold that doctors could place where a patient's nerve has died. Though the implanted nerve would not transmit signals itself, the presence of the living tissue could guide the body's regenerating nerve back to the injury site while keeping the detached nerve sheath intact. To get the engineered nerves to grow long enough to span the injured area by the time they were transplanted, he applied slight, gradually increasing physical tension; this process, he found, encouraged nerves to grow almost 100 times as fast as scientists had believed possible. Smith and his team introduced these engineered nerves into rats that had part of their leg nerves cut out. Within four months, as the natural nerves began to regenerate in the rats' bodies, the transplants had helped guide those nerves across the chasms, successfully restoring function to the rats' legs. ... so far, the longest nerve they have grown is approximately 10 centimeters. ... Smith hopes to start testing the human-derived implants in patients with nerve injuries in the next two years."