Industry News

Pfizer announces more retractions for sacked lab head Min-Jean Yin, whistleblower revealed

The pharma giant Pfizer announced to continue investigating the data manipulations committed by their former cancer researcher Min-Jean Yin, retractions of two more publications were requested and yet another paper’s fate is being currently decided. Again it is about studies of pharmacological inhibitors of cancer molecular pathways which Yin’s former lab at the Pfizer California research site has faked. These two retraction requests come is addition to 5 Yin retractions which Pfizer already announced on my site in October 2016 and which meanwhile happened. The PubPeer-listed evidence was first presented on my site in May 2016. Back then, the reader of my site, who posted that evidence of duplicated western blots on PubPeer and alerted me to it, preferred to remain unnamed. Now however, she agreed to be named: it was the microbiologist, image integrity specialist and host of the successful public outreach blog Microbiome Digest, Elisabeth Bik. She now forwarded to me this message:

“One of these papers had come up as part of the screen that I did for our study that was published in mBio, together with Ferric Fang and Arturo Casadevall (Bik et al 2016, as a [biorxive preprint here, LS]. Also as part of that study, we looked for other papers published by the authors, to see if there was an increased risk for problematic images among some authors. During that secondary screen I found multiple other papers with problematic images published by this San Diego group.

Since Pfizer does not have an institutional research integrity board like academic institutions have, I was not sure where to report these cases. I was also not sure how Pfizer would respond to such allegations. Therefore, I chose to report these papers through Leonid Schneider, in the hopes that Pfizer would respond. Fortunately, Pfizer did the right thing, and started an investigation. I have been very impressed with they way they responded.

Retracting these papers is the right thing to do for science. However, I am very sad about the personal consequences for the PI and all people who worked in that group. I realize that this has taken a big personal toll on all people involved”.

From Bik et al 2016: percentage of papers containing inappropriate image duplications by year of publication. Yin’s Pfizer papers are among those, unbeknownst.

After Bik’s anonymous evidence exposed Yin’s data manipulations, Pfizer sacked their company’s lab head of many years following an investigation. Yin was last known to work with a Californian biotech start-up Diagnologix LLC in San Diego. Since she deleted both her ResearchGate and LinkedIn profiles, it is not clear if that professional engagement is still valid.

Now, PLOS One and American Association for Cancer Research (AACR), two publishers which already had to retract four Yin papers, were asked to retract two more. On May 22nd, I received the following statement from Lucy Muzzy, Senior Corporate Counsel, GxP Investigations Lead, Compliance Division at Pfizer.

“Dear Mr. Schneider:

We write to inform you of additional investigative activities that Pfizer has undertaken relating to the image duplication concerns that you shared with us in 2016.  As Pfizer described to you in October 2016, we conducted a thorough investigation into the five papers originating from a particular Pfizer researcher’s laboratory for which image duplication allegations were raised on  We concluded that all five papers should be retracted and worked with the journals in question to secure official retractions of these five papers.  All of those five retractions have now been published.

Following this initial investigation, Pfizer proactively conducted a follow-up review of other published articles to which this laboratory contributed original research.  We want to make you aware that we at Pfizer have identified two (2) additional articles as having some data integrity issues relating to publication figures.  These articles are:

  1. R. Nassirpour, P. Mehta, and M. Yin, miR-122 regulates tumorigenesis in hepatocellular carcinoma by targeting AKT3, PLOS ONE 8(11): e79655 (2013).
  2. M. Walls, S. Baxi, P. Mehta, K. Liu, J. Zhu, H. Estrella, C. Li, M. Zientek, Q. Zong, T. Smeal and M. Yin, Targeting small cell lung cancer harboring PIK3CA mutation with a selective oral PI3K inhibitor PF-4989216, Clinical Cancer Research20(3): 631-43 (2014).

In the PLOS ONE article, we concluded that there is a duplicate image in Figure 4A.  In the Clinical Cancer Research article, we concluded that there are several duplicate images and related problems with the western blot figures displayed in the article.  On the basis of these findings, Pfizer has written to PLOS ONE and Clinical Cancer Research requesting retraction of these articles and has attempted to communicate with all co-authors of each paper.  To date, we have succeeded in reaching the vast majority of them.  All co-authors who have responded to our attempts to contact them have either concurred with the decision to seek retraction of their article or have, in the case of a small number of co-authors, not provided a substantive response.

There is one additional article for which Pfizer is evaluating whether remedial action, such as a correction to one or more figures, is required.  We expect to complete this internal review shortly and will let you know when it is complete.

Apart from this one additional article for which our internal review is ongoing, Pfizer believes that all material problems appearing in published articles that originated in the laboratory in question have been identified, with appropriate corrective actions taken. Given your correspondence with Pfizer last year regarding the image duplication concerns raised on, we wanted to share with you this update.  As we stated to you last Fall, data integrity is paramount to Pfizer’s Research and Development efforts, and we therefore thank you again for bringing the allegations to our attention.”

Update 21.08.2017. I received today this follow-up email from Pfizer, announcing a correction of a Yin paper:

“Dear Mr. Schneider,

I write to follow-up on the email that I sent you in May, attached below.

We have completed our evaluation of the one additional article that I mentioned in my previous email.  That article is the following:  J. Yuan, P. Mehta, M. Yin, S. Sun, A. Zou, J. Chen, K. Rafidi, Z. Feng, J. Nickel, J. Engebretsen, J. Hallin, A. Blasina, E. Zhang, L. Nguyen, M. Sun, P. Vogt, A. McHarg, H. Cheng, J. Christensen, J. Kan and S. Bagrodia, PF-04691502, A Potent and Selective Oral Inhibitor of PI3K and mTOR Kinases with Antitumor Activity, Molecular Cancer Therapeutics (Nov. 2011). [link here, -LS]

Specifically, Pfizer found that Figure 6C in the Molecular Cancer Therapeutics article does not accurately represent the underlying data for that experiment.  Based on this finding, Pfizer commissioned a review of the entire article and has concluded that all data in the paper, apart from Figure 6C, are accurate and that the unsupported result depicted in Figure 6C does not materially affect the findings of the paper.  Therefore, we have written to Molecular Cancer Therapeutics requesting that the journal remove Figure 6C and modify the corresponding Figure 6 caption and single line of text in the manuscript that references Figure 6C, through the issuance of a correction.

As I mentioned in the previous email, Pfizer believes that all material problems appearing in published articles that originated in the laboratory in question have been identified, with appropriate corrective actions taken.  Thank you for raising the allegations to our attention.

Best regards,

Lucy Muzzy

Senior Corporate Counsel, GxP Investigations Lead, Compliance Division, Pfizer, Inc”.


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11 comments on “Pfizer announces more retractions for sacked lab head Min-Jean Yin, whistleblower revealed

  1. Great work Elisabeth Bik!


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  4. So much for “big pharma” always being the dark side. Many academic institutions and publishers would be well advised to take a look at how Pfizer has handled this particular case, and learn some lessons.


  5. Volker Lauschke

    Very impressed by Pfizer’s actions. Much better PR than a scientifically-invalid paper sticking around.


    • Ana Pedro

      The pharmaceutical companies should look forward to have their own research integrity and ethical office


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