Amid the discussion generated by a paper that reports gene editing in human embryos, the process behind its publication has also aroused curiosity.

Lead author Junjiu Huang of Sun Yat-sen University in Guangzhou, China, says that the paper, published on 18 April in the Beijing-based online journal Protein & Cell (P.Liangetal.ProteinCell;2015), was rejected by Nature and Science, in part because of ethical objections. Both journals keep details of their review processes confidential (Nature’s news team is editorially independent of its research editorial team), but acknowledge that gene-editing of human embryos is a complicated issue for them.

“This is a rapidly evolving and complex area for which we cannot — and should not — easily offer simplistic policies,” says Ritu Dhand, editorial director for Nature. Nature Publishing Group is consulting with a range of experts to develop a “progressive policy” on the issue, she says.

Science, meanwhile, told Nature’s news team: “We believe strongly that the potential of genome editing must be viewed in terms of social mores and that the path forward must be developed through a consensus-building process.”

Emilie Marcus, the editor-in-chief of Cell and chief executive of Cell Press, says that her journals “would be open to considering papers on genome editing in the human germline” if they met high technical and ethical standards and that her team is “mindful of the complex ethical concerns and potential societal impacts” associated with such studies.

The editors of Protein & Cell say that they published the paper to “sound an alarm” about such work. “In this unusual situation, the editorial decision to publish this study should not be viewed as an endorsement of this practice nor an encouragement of similar attempts,” wrote Xiaoxue Zhang, managing editor at Protein & Cell, in an editorial published on 28 April (X.ZhangProteinCell;2015). “We had serious discussion about the ethics of this issue,” adds the journal’s editor-in-chief, Zihe Rao. “We expected there might be difference of opinions, but it needs to be published to start discussion.”

Springer, the publisher of Protein & Cell, confirmed that the journal had checked the researchers’ institutional approval and the consent forms from the embryo donors. They also confirmed that the study was compliant with the Helsinki declaration on human-medical-research ethics and with Chinese law.

The paper sped through Protein & Cell’s review process: it was submitted on 30 March and accepted on 1 April. A spokesperson for Springer said that the paper was submitted with peer-review comments from Nature and Science and that the authors had made revisions on the basis of these, which facilitated the fast review. Another round of peer review was conducted in the two-day gap between submission and acceptance, said the spokesperson.

Two days is “quite long”, says Rao. “You can e-mail the article to everyone at once. It’s not like the old days.”