Right away we realized that we had a diagnostic test and the diagnostic test at that time was fairly insensitive, but it was the beginning of other much more sensitive tests and we actually developed a radioimmunoassay using sort of standard radioimmunoassay methods and we patented that and that was the beginning of a huge industry. Within a few years it was a billion dollar assay measurement. The... I remember I talked to some people in Abbott, and we'd given them this reagents and they established the test and I met with them a few years after that started and one of their executives said, ‘You know we didn't have a diagnostic division until we got that test’. And that started what's now one of the major big pharm diagnostic companies. And I remember a colleague of mine was… was at Stanford and he started using the test very early and he pointed out something which in a funny way I hadn't realized; you know, prior to this test there wasn't a direct method of attempt to find a virus. When I was in, doing clinical work, if you thought somebody had a viral disease, you collected an… an acute sample and then a convalescent sample some months later — weeks later or months later sometimes—and then you could see if there was an increase in titer, of a particular antibody. So you… you could diagnose he had it, but you couldn't actually do it at the time. This you can do, well, subsequently in hours, but certainly overnight at that time, so it was a big step forward in… in the direct testing of viruses and it had a big impact. In a funny way I didn't realize that at the time, primarily because we were on to other stuff.