 Is it related? Is it a different version of the same bacterium or something like that? Because I think this all sort of originated, I thought, in the steppe or something in about 5,000, 6,000 years ago. Yes, so that was what we believed until recently, that it came with the steppe people in the Bronze Age. But now it turns out that it was actually present in Europe before that, so with the farmer population. And we know, we can see now that it's an ancestor to the strain that caused the Black Death.