million have people. 170 billion. and the answer to your question, if you look at the last two decades we ve gone from understanding that this is a reality, to really understanding on the imaging that there are on mri s and cat scans, there are lesions on the white matter on the brain that could cause this, we had a segment not too long ago we talked about beta amyloid, plaques that kind of block the formation to go from one side of the brain to another one and they freeze their talking and thinking and all of a sudden they forget. so we ve come a long way and now we re coming closer and closer to the secrets and decoding the the genes. what they re finding out british scientists, after looking at over 2000 patients and looking at their genes, they ve come up with a new finding called tren 2, tren 2 is the new gene that a lot of patients with alzheimer s has it. it s interesting, as we think and as we get older, there s a lot of debris around our brain just like anything else. there ar