They are looking for the bloodline.

Weird story. A man who worked at my apartment was cleaning the pool about 6 years ago and he seemed upset and said I need to tell someone what happened at my doctor’s appointment. He had a blood test and when he went back for the results there were 2 men who seemed like government agents just standing there with his doctor. They said nothing and just listened as his doctor told him he had a super rare blood type and asked him how long his father lived and other questions. His father died at 103, I think. He was shaken by the whole thing and asked me what I thought about it. I didn’t know what to make of it.