where you take a little bit of cerebral spinal fluid from someone's body and analyze that. take a look at it. and what researchers were focusing on, proper two proteins. they are sort of a signature for alzheimer's disease. here is what they found that was so interesting and exciting as well. they looked at three groups of people. people with all timers and people that had mild memory problems and people that had no memory problems. the people that had known alzheimer's almost with 100% predictability it was able to diagnose that they did have alzheimer's. again, from that spinal tap test. then people that had mild memory problems, about three-quarters of them had this abnormal set of proteins in the fluid. all of them within five years got alzheimer's. that's the amazing thing. if they got the abnormal test result, all of them within in mild memory group went on to develop alzheimer's within five