Hisashi Moriguchi in a picture from 2012. {credit}AP/Press Association Images{/credit}

He’s back.

Last autumn, Hisashi Moriguchi stunned the world of stem-cell science by claiming he had become the first person to transfer induced pluripotent stem (iPS) cells into patients. In a now infamous front-page spread in the Yomiuri Shimbun — which has the largest number of subscribers of any newspaper in the world — Moriguchi said he created a type of iPS cell, differentiated them into cardiac cells and treated six patients with heart failure. One, he said, had already recovered and was living a healthy life.

But in an interview with Nature on the day the story appeared, Moriguchi’s claims quickly fell apart. Nature found that a paper that had supposedly set the foundation for the work was largely plagiarized, that Moriguchi had lied about his training, that he couldn’t name collaborators and that the facilities where the procedures supposedly took place had no record of them.

He also prevaricated about his affiliations — claiming in publications, for example, to hold a position at Harvard long after the short-term visiting fellowship he held in 1999–2000. Under fire, Moriguchi admitted to many false statements. Several papers were retracted. He maintained, however, that one procedure had taken place.

But Moriguchi has not rested on his laurels since then.

He has had three papers in the past two months in the peer-reviewed medical journal BMJ Case Reports. In one, published online on 18 April, he claims to have supercooled oocytes to preserve eggs from the ovaries of patients with cancer, so that the patients can later use them for in vitro fertilization. That paper, judging from the abstract, which has almost identical wording, seems to be a plagiarized version of a paper he retracted last autumn.

In a second paper, published online on 2 May, he again claims to have used iPS cells to defeat disease — this time, liver cancer. It is unclear from the summary whether he claims to have already accomplished the feat or just achieved a proof of principle.

In a third paper, published online on 24 May and reminiscent of last year’s controversial announcements, he claims to have transplanted iPS-cell-derived cardiac cells into a patient with heart failure.

In all three papers, he is the corresponding author. In all three, the other author is Joren Madson, whose affiliation is given as Reprogramming, Inc. in Boston, Massachusetts.

Nature has not been able to confirm the existence of a Reprogramming, Inc., in Boston or of a researcher named Joren Madson.

Nature has also not been able to confirm the existence of a company called Reprogramming, Inc., in Chiba, Japan, where Moriguchi claims to have an affiliation. Moriguchi’s e-mail address as the corresponding author is provided by the University Hospital Medical Information Network (UMIN) Center, an organization that acts as a clearing house for clinical-trial data. But a UMIN representative says that Moriguchi does not have a position there. E-mail addresses are given out to anyone who registers on the site.

In an e-mail, Moriguchi responded to Nature’s request for more information:

“Thank you very much for your interest. This week including today is difficult as I am in hospital. In another days (next weeks, etc), I appreciate if I can discuss about the issue via e-mail. I look forward to hearing from you via e-mail.”

Nature alerted BMJ Case Reports to the articles yesterday (13 June); a press officer says that the journal is looking into the matter.