 Blood samples, I mean, I don't know, I'm kind of groping around here in the dark, but go ahead, yeah. Yeah, you're not groping at all. In fact, one of the most promising avenues for early detection right now are multi-cancer early detection liquid biopsies that are being developed. And the advantage of these are that they're using molecular signatures that are floating around in the blood to identify the presence of cancer very early. So they're not really ready for prime time.