so if you wake up with a stroke and come to Stanford and we take a picture and it looks like this we're going to go after that blood clot if you show up two hours into the stroke and the tissue is already massively injured we're not going to remove the blood clot we're going to try to do something to reduce the swelling because a big stroke it's going to cause even more trouble from the swelling so it's a great question but that's the rule of the FDA yeah what difference genetic differences between people it would say some people