I think many of us in the stem cell field still find it fairly easy to recall the time when we first heard about iPSCs (induced pluripotent stem cells). For me, it was at a Keystone meeting back at the end of March 2006, when Shinya Yamanaka presented his and Kazu Takahashi's work showing that they could reprogram mouse somatic cells back to a pluripotent state using just four transcription factors.

One of my most vivid memories from that meeting is not actually of the talk itself—although that was also quite memorable—instead, it's of sitting in the ski rental shop trying on ski boots when Shinya walked past and told me he had decided he would submit the paper to Cell. That choice came on the back of a conversation we'd had the day before, after his talk. Many in the audience were amazed and excited about what they'd heard, and, as you might expect, Shinya was somewhat mobbed by eager questioners, one of whom was me. The next day, he made my afternoon with that short sentence.

By the time we got to the ISSCR (International Society for Stem Cell Research) annual meeting in June, the 2006 paper was already well on its way toward being accepted for publication. This meeting is the largest annual gathering of stem cell scientists, so the audience was quite a lot larger than at the Keystone symposium, and the excitement was palpable. Although some people said they could see all of the implications even then, I think for most in the audience there were still some questions about how robust and reproducible the process would really be, and whether it would also work for human cells. Of course, all those questions were answered in the following year, and after that the iPSC phenomenon was up and running.

When Shinya gives talks about the discovery process, he is always very careful to give appropriate credit to people who had worked before on other cell fate conversions, including transcription factor-based switches, such as Harold Weintraub's work with MyoD, plus, of course, John Gurdon's work in Xenopus, which showed that reprogramming to pluripotency was possible at all, in any system.

Some commentators argue that this previous work was the real breakthrough and that iPSCs were more like an adaptation. I don't agree. From my perspective, iPSCs changed everyone's view of what would actually be possible with reprogramming—if we can get mammalian cells to do THAT with just four factors, what else can we get them to do?—and opened up many doors for new avenues of study and application. There's a reason why the whole field took off so quickly from 2007 onward, and I'd argue it was because so many people could see the potential, plus they also felt (and then found) that it was something that they themselves could do.

Hans Schöler made a similar point in the excellent Conversation article in Cell earlier this year (which I would encourage you to read if you want some more historical perspective on how the field reacted at the time). As Hans said,

"The publication of the 2006 and 2007 Yamanaka papers has opened the minds of many researchers to see if they could find cocktails that would be able to convert somatic cells into other different cells and to understand the barriers that need to be overcome in order to obtain stem cells."

This Conversation article was part of a broader series of articles that the Cell and Cell Stem Cell teams have proudly collaborated on over the course of this year, put together to celebrate the 10th anniversary of the groundbreaking 2006 paper. You can find all of the articles gathered together on this special commemorative page. I hope you've enjoyed all of the various reviews, commentaries, and discussions that have come together to make up our feature.

Some of you also chose to join us at a special Cell Symposium in Berkeley in September, where a broad range of speakers covered iPSC-related topics that ranged from basic insights into reprogramming mechanisms to challenges related to clinical application. We were able to squeeze in some fun, too, with early morning exercise and an elegant dinner, and some of us, including yours truly, are still enjoying our souvenir OSKM T-shirts!

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Of course, even as we look back and think, "Wow," we also look forward and think, "What’s next?" Some of the most rapid periods of advances in science come from the development of new techniques that allow us to ask questions in ways we couldn't before (right now, think of single-cell technology and CRISPR/Cas9 and the way they're opening up new avenues of research).

The discovery of iPSCs was different in that it was a conceptual as well as a technical breakthrough, but it, too, led us to a whole new world of discovery, particularly for human cells. Just think how much we have managed to learn already about human disease using iPSCs, and how much more we'll be able to find out once we've perfected the techniques even further and combined them with other approaches like GWAS and systems-level analysis. Then, of course, there's also the possibility of using the cells themselves directly in therapeutic settings, something that's already a major focus of research and clinical effort, particularly in Japan. The possibilities are enormous, and I can pretty much guarantee that even people working at the forefront still haven't thought of them all.

Probably because I'm an editor, I often get asked to break out my crystal ball and predict the future, or give some idea of where the field is going. In some ways, I wish I knew (it might make my job quite a bit easier…), but overall I am very glad I don't. Just like that first talk on iPSCs, the discoveries that excite me the most are the ones that come out of the blue and really make me think differently about what is and is not possible. Those types of findings don't come along all that often, but when they do they shape the field.

So rather than try to act as a soothsayer, I am happy to watch and wait—somebody out there has something cooking! And in anticipation, here's to the next discovery that has as much of an impact as iPSCs, whatever that turns out to be.