Nobel laureate and renowned physician and scientist Gregg Semenza is facing more than 15 additional paper investigations from various publications, an investigation conducted by Nature has found. Semenza has already seen 17 of his papers retracted, corrected, or raised for concern since 2011. Four were retracted from PNAS just last month. Of the 17 papers of concern, five were retracted as a result of image manipulation, Nature reports.
Semenza shared the 2019 Nobel Prize in Physiology or Medicine with two other scientists for his work on cellular oxygen regulation, and shared the Lasker Award for basic medical research in 2016 for the same work. However, even before he received these awards, some scientists were suspicious of his published results. Users on the website PubPeer, which allows commenters to flag apparent errors or fabrications in published research, have found potential problems in 54 publications on which Semenza is an author.
“I saw problematic Gregg Semenza publications before his Nobel,” pseudonymous PubPeer user Claire Francis tells Retraction Watch. “I recognized his name when he got his Nobel Prize and went back for a second look.”
Although many of the papers flagged on PubPeer were published prior to 2016, the vast majority of the PubPeer allegations were posted in the last two years, with 14 posted in the past month. Among 32 papers that have either been retracted or are under investigation by their publishers, Semenza is a corresponding or co-corresponding author on 14, Nature reports.
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For the amount of work that comes out of Semenza’s lab, having 17 papers corrected or retracted over a decade is not out of the ordinary, Elisabeth Bik, an image-integrity consultant who has investigated errors in Semenza’s papers, tells Nature. However, having five papers retracted for image manipulation is “much more than one would expect,” she adds.
The majority of the image manipulation concerns voiced on PubPeer center around the reuse of the same data or images in different figures within each paper and across different papers, with users citing the similarity of small elements within the figures. This same issue caused the retraction of the PNAS papers, Retraction Watch reports. Other publications have cited the “splicing” of parts of different images to create a composite picture, Nature reports.
An anonymous researcher in Semenza’s field tells Nature that the papers flagged on PubPeer and under review at journals published by Springer Nature are not those with the highest significance to the overall field, but scientists are awaiting the results of the investigations with “a mixture of concern and interest.” The four papers retracted from PNAS in September alone had been cited more than 750 times, Retraction Watch reports, adding that Semenza was a principal investigator on grants from the US National Institutes of Health (NIH) totaling more than $9 million from 1998 to 2013.
The journals currently investigating Semenza’s papers include Nature Genetics, Oncogene, Science Signaling, and The Journal of Physiology, Nature reports. Seven other publications that have published the flagged papers have acknowledged the criticisms but declined to comment, Nature adds.
“The fact that there are multiple papers now retracted for manipulated images, and several others still under investigation suggests an intention to mislead,” Bik tells Nature.
Correction (October 22): An earlier version of this article stated that 17 of Semenza's papers have been retracted; in fact, 17 have been retracted, corrected, or had concerns brought up about them. Five of those papers have been retracted. The Scientist regrets the error.