The next series of events had to do with further convincing ourselves that this was a correct interpretation because Paul and I were both about the same age. We were still young men, starting our careers. And because I knew many of the major personalities in the field of cell culture – by this time I had been teaching the annual tissue culture course that my former boss Laurence Steinbering had brought to the laboratory when I was a student at Penn [University of Pennsylvania]. I was now involved with actually teaching in that course and through that mechanism had met most of the major figures and could easily talk to them and approach them.

Several of them, I remember distinctly one individual in particular, that was George Gey, the man who discovered the HeLa cell and a balance salt solution which was part of the technology that has his name to a particular formulation – George and I were pretty close friends, we had met each other at the annual cell culture course in addition to which his mentor, a man by the name of Warren Lewis, another pioneer in cell culture, had retired from two or three institutions, including Johns Hopkins, where George Gey worked, and Warren Lewis was still living and working in his laboratory on an upper floor of the Wistar Institute during the events that I just described and I got to know Warren. Of course, he was a highly-respected man in his 90s. His wife was still living. She was also a well-known scientist and George came to visit them frequently and I would meet him on those occasions.

George, who by then knew about my work, said, 'Lenny, you're going to get yourself in a lot of trouble.' He was a very outspoken fellow which I admired. 'You're going to get yourself in a lot of trouble if you publish this because there must be some error going on here.' I said, 'George, you know the experiments that Paul and I did. We can't see any hole in these experiments.' 'I don't care', he said, 'there's something going on, you know, this has been known for 60 years that cells are immortal.' And furthermore he reminded me of something that I should address now and so I'll make this diversion, and that is that there was a key experiment done in the field of cell culture in the mid 19... actually, in the early 1900s, from roughly 1910 or 11 up until the 1930s, early 40s. This key experiment, known to many people, even many people in the public, was an experiment done by a man whose name is Alexis Carrel.

Alexis Carrel was an unusual personality. On the good side, I suppose it can be said that he raised cell culture to a level of visibility by the public and by scientists in general. I think that was... probably can be called a good thing, but he probably had more negative things about him than excellent qualities. First of all, in the non-scientific realm, he was essentially a fascist. He was working – he did the work that I'll describe in a moment – at the Rockefeller Institute in New York which it was then called. The work he did was to claim that he had cultured cells from a chick heart for over... for close to 40 years. Well, of course, that flew in the face of my observations. How is it possible for chick cells to replicate so many times, over 40 years and apparently, although he didn't know this for sure, apparently remain normal. As I say, that was not known for sure, but what was known was that there were no transformed chick cell populations known in the 60s when work with chick cells was very widespread throughout the world. One couldn't culture chick embryo fibroblast more than 15 or 20 population doublings. That also argued against what Alexis Carrel had changed.

Going back to his political stance which has some bearing on these scientific events, he published a book that became widely read called Man: The Unknown in which he expressed his right-wing fascist viewpoint and indeed his serious anti-Semitic attitude. I should say, as an aside, that I was involved with another gentleman in this field to persuade the authorities in Paris to remove his name from a street named in his honour in Paris and I'm happy to say that we were successful about three years ago. Alexis Carrel, to finish the political side of his career, left the United States and became part of the Vichy government as a Nazi sympathiser.

Returning to his laboratory work, he was a surgeon by training, a physician. In fact, he won a Nobel Prize, not for the cell culture work that I'll describe in a moment, but believe it or not, for a surgical knot.