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Mar. 14, 2014 Press Release Other

Interim report on the investigation of the Obokata et al. articles

RIKEN takes very seriously the various allegations and concerns that have been raised regarding the two STAP cell research articles published in the journal Nature by researchers at the RIKEN Center for Developmental Biology (CDB), and has established a committee to investigate the concerns.

The investigation is currently in progress and it will be some time before a final report can be issued. Given the high interest in this case, however, the committee has issued an interim report on the six items it is investigating, including those for which it has reached conclusions and those items that are still being investigated.


  • The committee concluded that there had been inappropriate handling of data for two of the items under investigation, but the circumstances were not judged to constitute research misconduct.
  • There are four items that are still being investigated. A report will be issued on the items still under investigation as soon as all the facts have been thoroughly assessed and conclusions have been reached.

  • 1. Circumstances

    On February 13, 2014, the RIKEN office in charge of compliance issues was notified of concerns that had been raised regarding certain papers published by RIKEN researchers. A preliminary inquiry as required by RIKEN regulations was immediately launched on that same day, and given the seriousness of the issue, it was decided that a more thorough, scientific investigation was warranted. On February 18, an investigative committee headed by Dr. Shunsuke Ishii, Distinguished Senior Scientist, RIKEN Molecular Genetics Laboratory, was established to investigate the papers in question.

    2. Individuals being investigated

    Haruko Obokata
    Unit Leader of the Laboratory for Cellular Reprogramming, RIKEN Center for Developmental Biology

    Yoshiki Sasai
    Group Director of the Laboratory for Organogenesis and Neurogenesis, RIKEN Center for Developmental Biology

    Hitoshi Niwa
    Project Leader of the Laboratory for Pluripotent Stem Cell Studies, RIKEN Center for Developmental Biology

    Teruhiko Wakayama
    Previously Team Leader of the Laboratory for Genomic Reprogramming, RIKEN Center for Developmental Biology, currently professor at the Faculty of Life and Environmental Sciences, University of Yamanashi

    3. Investigation methods

    Starting on February 20, the investigative committee has been reviewing documents and other relevant materials and interviewing the individuals involved.

    4. Items being investigated and results

    I. Items on which conclusions have been reached

    (1) Obokata, et al, Nature 505:641-647 (2014) Article (Paper 1) “Unnatural appearance of colored cell parts shown by arrows in d2 and d3 images of Figure 1f”
    It was concluded that the process of preparing these images did not constitute fabrication within the context of research misconduct.

    (2) Obokata, et al, Nature 505: 676-680 (2014) Letter “Strong resemblance between the rightmost panel in Figure 1b and the lower panel in Figure 2g, both showing a fluorescence image of mice placenta”
    There is no reference to the figures in either the figure legends or the main body of text, and this discrepancy is within the context of fabrication as defined by RIKEN’s regulations on research misconduct, but there was nothing to contradict the explanation that one of the figures had inadvertently been left undeleted during the process of manuscript creation. It was therefore concluded that there was no malice intended, and this was not judged as a case of research misconduct.

    II. Items still under investigation

    (1) Paper 1: “In Figure 1i, lane 3 appears to have been inserted later”

    (2) Paper 1: “A part of the Methods section on karyotyping analysis appears to have been copied from another paper”

    (3) Paper 1: “Some of the description of karyotyping in the Methods section is different from the actual procedure that was followed”

    (4) Paper 1: “The image of differentiated cells for Figures 2d and 2e and the image of chimera mouse immunostaining data are incorrect, and in the process of the investigation, it was found that these images closely resemble images used by Dr. Obokata in her doctoral dissertation”

    5. RIKEN’s basic stance

    We have received a number of comments and opinions regarding this issue which has also been widely taken up on the Internet and by the media. We consider it our responsibility to respond in the following four areas.

    (1) Confirmation of whether there has been research misconduct

    (2) Reproduction of STAP cells

    (3) Handling of the two papers published in Nature

    (4) Future measures

    6. Future preventive measures

    While the investigation is still on-going, we are currently deliberating the following measures in response to the conclusions that have been reached to date.

    (1) Disseminate throughout RIKEN points on which researchers should be especially careful in preparing their papers

    (2) Drafting of RIKEN guidelines for submission of research papers

    7. Next steps

    The investigation is still in progress and there remain allegations and concerns that must be thoroughly investigated. RIKEN takes this matter very seriously and considers it essential that the facts be ascertained. As soon as the committee has reached its conclusions, a final report will be promptly issued.


    President Noyori comments

    English translation of the Investigative Committee’s Interim Report


    Jens Wilkinson
    RIKEN Global Relations and Research Coordination Office
    Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-463-3687
    Email: pr[at]riken.jp