Now, returning to the original paper which has a very interesting story, Paul and I are still very hesitant – he was the co-author with me on the original paper. There are actually two papers that describe virtually everything; the first one was authored by myself and Paul, the second one was authored by me alone. We were still, with some trepidation, worried about publishing this work, young men starting their careers, you make a major error like this and you're finished. At least, you'll suffer considerably. Consequently, I decided to do, 'an experiment', that you won't find reported in the paper.

I decided that because I knew several of the major grey eminences in the field at the time, I would pick up the phone, call them and tell them that I would appreciate it very much if they would accept a culture of my normal human cells, culture them in their lab under their expert guidance and that if this was, let's say June of this year, that you would call me in December of this year and tell me that the cultures I'm sending you – if you agree to it – next week have stopped dividing. 'Oh, okay, we don't believe that at all but, as a favour to a young scientist, we'll do it.'

So I sent cultures, I think, to Harry Eagle – a major personality in the field whose name is given to a media formulation that he developed that's very commonly used, even to this day – George Gey, of course, and I don't recall who else I sent to. Sure enough, December came around, the phone rang from all three of these gentlemen; 'Len, the cultures you sent us have stopped dividing.' Well, I figured if that has occurred and if I'm wrong, when I go down in flames, I'm going to have very important company. That you will not find that story in the Materials and Methods section of the paper.