Milton Leitenberg: Looking at very, very minute changes of base pairs in a couple of plasmids, separate little pieces of DNA, that's where they found that there were four or five slightly different inversions. There would be two or three base pairs that had a different sequence. And they found four or five of those. And right away, some people grabbed that, and said, "Ah, there's four or five different strains." No. Not four or five different strains. They had been culturing in Sverdlovsk, whatever the strain is, for we don't know how many generations. It's very likely that those developed right in that strain, the Russians would never, never have known even, that there were these base pair differences, unless they had done that analysis. But in fact, that degree of... of genetic analysis only became available in the last couple of years. In fact, it led to the business with Ivins, with you know, who... who did the letters here. So, these were extremely refined, secondary, and tertiary analyses. They weren't the basic analysis of the basic strain. And that's where this notion of four or five different... there were not four or five different strains.