Stem cell tragedy: Yoshiki Sasai (笹井芳樹) commits suicide

Dr. Yoshiki Sasai
Dr. Yoshiki Sasai (笹井芳樹) .

Dr. Yoshiki Sasai (笹井芳樹) former Deputy Director of the RIKEN CDB and a senior author on the STAP papers, has reportedly died from suicide.

Update: The Japan Times writes on this situation that Sasai was found hanging at RIKEN and there may have been a suicide note.

Dr. Sasai was a top scholar in the stem cell field. He published dozens of high-impact publications and was widely respected.

You can see some thoughts on the loss of Yoshiki Sasai from Scientific American here by Janet D. Stemwedel.

The Sasai lab has focused on many important stem cell and developmental biology projects. His research in many ways established the foundation for stem cell-based organoids, including those in particular of the nervous system.

This is a tragedy and thoughts go out to his family, friends, and lab members.

You can see a tribute I put together for Dr. Sasai here, which was signed by many members of the scientific community.

In 2015 I also did a piece more generally on why scientists commit suicide and perspectives on what that may teach us about problems with the culture of science.

I wondered if there was a way to address this problem:

“There’s not a whole lot of compassion in the community of science for scientists as actual people. I’m not sure if there’s a way to change that. It would be helpful if there were less stigma for scientists who have mental health issues. Science needs more resources available to scientists who may feel in a particularly hopeless situation at a certain time with nowhere to turn.

More research on suicide by scientists is needed as well. Remarkably there are almost no scientific articles on suicide by scientists. For instance, see this PubMed search result, which yielded just 4 articles out of the >23,000 with the title word “suicide”. So we are pretty much in the dark in terms of scientist suicides, trends, causes, and such. It seems to be one of those taboo topics that in reality needs more open and thoughtful discussion.”

23 thoughts on “Stem cell tragedy: Yoshiki Sasai (笹井芳樹) commits suicide”

  1. The journal Nature finally retracted the STAP paper. More than retraction of a paper…. it resulted in the retraction of someones life too- Sasai. He committed suicide (may be suicide?) yesterday. Share responsibility! The funders, the publishers, the universities! A reasonable editorial process would have perhaps prevented a death! Publishing business where little editors strive to thrive in their little kingdom below the senior management and the Chief Editor. These princesses (‘statistically’ speaking-counting heads from a recent issue) have little interest in science when they struggle for a little raise! Who has interest in double blind peer-review in big journals or big grants? Neither big scientists nor big journals! Scientists such as Rany pointed out the flaw of the system but who cares a Nobel winner! If so who cares an average scientist? Hail Randy!

  2. Pierre Balenciaga

    >Please don’t punish her anymore.

    That’s what they call wishful thinking.
    Her misconducts must come under public scrutiny.

  3. Matthias is right, and besides the human side of tragedy it is time for high impact journals to up their game. As funding systems and these journals created/set the standards for “publish and perish” policy, its unintended consequences more frequently lead to fraud and manipulations. They are also responsible. Normally the basic research never goes in straight line

  4. I am writing this comment to all of scientists overseas.

    I feel so sad of this news as one of Japanese citizens.
    I really want to pray for his R.I.P

    Since this event happened, I was watching how the situation goes carefully and was worrying about someone’s committing suicide.
    I heard he was good person as scientist and as a individual,so, I am so disappointed about his death.

    But I really would like to ask all of you to stop scapegoating on just one of co-authors,especially Dr.Obokata.
    Here In Japan, she has been attacked by medias and others not as a scientists but as an individual.
    No one don’t deserve this kind of harsh attack.

    And now ,Dr. Obokata started to verify the STAP theory in the lab with surveillance cameras.
    *She had not been allowed to enter the lab for a couple of months,even though she had claimed that she is innocent on falisification of the result.

    The only way for her to prove her own innocence is to have another attempt on the experiment again.

    After the another experiment, it will be clear that 1)the STAP theory is true or false or partially true (false), 2) what the cause is, and 3)how co-authors should share the responsibility.

    I understand all of scientists have been so irritated over the STAP, because many have wasted their time to confirm the STAP theory.

    However,I sincerely ask not to jump to the conclusion, such as that all the flaws in the theory are Dr. Obokata’s fault, or that she might have falsified the result of study, resulting in people having negative image on her as a person,anymore.

    Please watch over her verification with generosity.

    I will be happy if you consider this event from non-scientific perspective, like me.

    Best regard.


    a)3 institutions with different background-RIKEN, Tokyo Women’s Medical University, and Harvard University were involved in this study, which means it was so difficult to communicate with each other and may have been communication gaps.

    b)Recently,I sometime feel Japan is not normal country anymore,because people here are always searching some scapegoat.

    Sadly, it seems there are no rational person here.

    I believe there is no country like here,which broadcast fake story such as that there was inappropriate relationship between Dr.Sasai and Obokata,or she made up her face to look so pale on press conference for drawing attention.

    As I said this burden is too heavy for one person to shoulder.

    I dare to ask again.- Please don’t punish her anymore.

  5. Let’s remember Dr. Sasai’s impact on our field from all of his great work in the past. Let’s pay tribute to what great science he had accomplished and the genius in his head that could conceive the truths we are coming to benefit from. Historically, his work was impeccable and fundamental.

    I personally believe that he was shamed by the STAP fiasco and had become so distraught by it as it seemed to overshadow everything he had done. We scientists were fast to cut him down for his involvement, and yet his faults of being famously overworked and trusting of his subordinates are faults that could have happened to many of us in the same shoes.

    In this loss, we should reflect upon his 30+ years of great work. And in such, possibly we can learn a more tactful temperament for how we react to errors in our field. Collectively, the scientific community shamed him and did so unrelentingly; and quite often in such criticism, his amazing precedence was ignored. We watched the journal Nature cower and point fingers despite their own involvement. We saw the same happen for Dr. Vacanti, who seems to have exited the debacle unscathed.

    At the end of this day, we should know that every scientist is human. I’ve got my heart out for Dr. Sasai, his family, and colleagues. He did not deserve such excessive criticism for human error — and he may have deserved a little more respect when people questioned him. Let’s hope that in the future, we scientists can move forward from this with our facts and thoughts, but also with the appreciation and respect for each other that we so deeply require.

    1. His broader contributions to science are exceptional and must be his legacy. He deserved more respect when people questioned him.

      1. In my honest opinion, Dr. Sasai was worn down far more by the local media than by any amount of finger-pointing by his peers (not to minimise the importance of peer critique, of course).

        The Japanese media, for recent historical reasons that are too long-winded to go into here, were absolutely relentless in their hounding of the concerned parties. The Japanese public were more than happy to go along. I heard that RIKEN received hundreds of phone calls from disgruntled tax payers, and all sorts of nasty and unsubstantiated rumours were flying about regarding the nature of the relationship between Sasai and Obokata and others beyond. The tabloids especially had a field day, but so did the more respected media outlets.

        I was utterly horrified, and so were most of my foreign friends here.

        Possibly the straw that broke the camel’s back was a forensic TV special about the whole issue that was highly critical of Sasai’s part. (I think it was broadcast last week? I didn’t actually watch it, and now I’m not sure I want to.)

        Whenever Japanese people ask me for the “gaijin” opinion about this whole STAP debacle, which they have been doing ever since it unfolded earlier this year, they always seem extremely concerned that it will reflect badly upon Japan.

        Dr. Sasai must have felt as if a whole nation, his own country, had turned against him. The consternation of his fellow researchers around the world would’ve paled in comparison, although obviously it wouldn’t have helped much, either.

        This blog has been doing a wonderful job of reporting the facts without fear or favour, and yes, giving the benefit of the doubt where is was due, without compromise. For that I salute you. Thank you.

    2. Gaikokujinnoiken

      I agree that Dr. Sasai was treated badly by the media and some members of the scientific community. But, I really feel there is one person who could have put all of these questions to rest had she been honest about her work. One thing that would lessen the blow of Dr. Sasai’s death would be for Dr. Obokata to face the media and scientific community alone, without her team if lawyers, and say what really happened. If she apologized and agreed to dedicate the rest of her life to some worthy cause, I think we could all forgive and put this painful chapter behind us.

  6. Dr. Matthias Siebert

    As somebody who lives in Japan and who has worked at RIKEN I can maybe provide some context to what might seem otherwise as a unusually drastic response (suicide) to a nowadays sadly frequent procedure (retraction of papers from high impact journals). It is important to know that when the STAP papers where first published there was a gigantic media hype here in Japan centered around Obokata, who was portrayed as the “new face of Science” in Japan. The image of researchers here is that of old, weird man, so a young woman, who was also seen as hip, made it not only onto the headlines of all normal newspapers, but also of fashion magazines and the like. The cloth she was wearing at the press conference were sold out at shops and the hype was lasting for weeks. So when the first doubts appeared this was also constantly in the headlines. And when the papers were retracted this turned into maybe the biggest scandal Japanese life science has ever had. Also RIKEN, an institution that had its first official case of misconduct in its over 100 year history in 2009, did take this issue very serious. With the outside commission going so far as to recommend the dismantling of RIKEN CDB the pressure must have been immense on the responsible people. So seen from this perspective the suicide is not so surprising at all. I kind of expected this to happen, although I would have thought Obokata would commit suicide first. Sadly I am afraid this might trigger a kind of chain reaction, as I can’t see how Obokata is supposed to reproduce her results when at every pipeting step she has to think of Sasai who killed himself over the issue. Also somebody from the outside committee might feel responsible and commit suicide too. I think this sad event calls back into peoples minds that Japan is not a “normal” country according to Western standards. Here responsibility is taken deadly serious and with a history of ritual suicide, which would wash off the sins of life, suicide is still very common. As Sasai has hanged himself, which is not the traditional way, it remains to be seen what he writes in his suicide note as to his motivation for doing so. Overall, even though as I said it does not come as such a surprise to me, I find this progression of events very worrying and disturbing. In the light of such a dire consequence as in the casualty of human life I think all groups involved (such as media, also the people at Nature who accepted the papers) should question their actions.

    1. Thank you, Matthias, for this insightful, important comment. All of us need to reflect on how STAP played out and see if we can find a way to a better approach in the future. We need to think about the broader problems in science today too that create an unhealthy climate.

      1. This is certainly a tragedy, and I find Mr. Siebert’s comment important. But allow me add a comment about suicides in Japan, as a specialist in East Asia history. I don’t think the high suicide rate in Japan can be explained only by the pre-19th century ritualistic suicides for the samurai class, which was a very small portion of the entire population even back then.

        From what I have so far read via Internet, Dr. Sasai probably had depression at least since March and was receiving treatments. I don’t know anything about his mental health caretakers, but in general, I know it’s hard to find good therapists there because psychotherapy isn’t normally covered by heath insurances in Japan…

    2. I feel so sad of this news as one of Japanese citizens.
      I really want to pray for his R.I.P

      Since this event happened, I was watching how the situation goes carefully and was worrying about someone’s committing suicide.
      I heard he was good person as scientist and as a individual,so, I am so disappointed about his death.

      ”Sadly I am afraid this might trigger a kind of chain reaction”

      This is exactly what I am worrying about.

      I really would like you to watch over her verification with generosity.
      This sad story was not made by just one person,but many facts were involved.
      It seems that punishing on just one person is not productive

      I don’t want to hear this kind of sad news anymore.

  7. I live within walking distance of RIKEN CDB. There were helicopters flying overhead all morning. At work, the topic of conversation was nothing else. We all have our thoughts about this.

    By the way, did you know that last week Ms. Obokata was chased in a hotel by five reporters, resulting in her being injured? They were NHK (Japan Broadcasting Corporation) reporters, but they were behaving like the worst sort of paparazzi. No, not even paparazzi, more like a pack of hounds after a fox.

    It’s a sorry, sorry thing. I greatly appreciate the restraint shown by foreign media when reporting on this case. And I know the whole debacle must have been very disappointing for fellow researchers worldwide, but you have behaved very fairly and even-handedly when reporting about this. Thank you.

    1. I heard about the NHK thing. That’s way too aggressive. It’s important to get at the truth and for there to be responsibility, but I think it must be done in a respectful way that does not attack the scientists. The focus should be on the science in question.

  8. Gaikokujinnoiken

    Neither Dr. Obokata’s stubborn refusal to take responsibility for this debacle nor Dr. Sasai’s taking ultimate responsibility through suicide are healthy ways of clearing things up.

    We should learn what went wrong and why so we can do better next time. I’m sure there will be some embarrassment and shame when the truth gets out, but nothing that warrants taking one’s own life! We’re all human beings, after all, and we make mistakes.

    I also wish the best for Dr. Sasai’s family, friends, and lab.

    1. True. We are all human and every scientist including each of us makes mistakes. His legacy is one overall of great, creative science and contributions.

  9. Dr M.Chandrashekhar

    Indeed sad. Our Heartfelt Condolences to his family & friends. Rest in Peace, Friend.

  10. so, so sad, terrible. The whole fiasco has been so unfairly scape goated on the japanese labs while Vacanti accepted initial praise and then washed his hands of the situation. The whole situation has been shamefully handled.

      1. That is a far bigger loss for the scientific stem cell community than the bad reputation the STAP cells brought.

        I really appreciated Prof. Sasai’s work and learned many things out of his publications. I always wanted to speak with him at a conference but never attended one where he was also present.

        That is a sad day.

        The people at his lab will never get a more knowledgeable supervisor is what I believe.

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