The British journal Nature Biotechnology said on Tuesday that it would look into a controversy over an article published by a team of Chinese scientists claiming a breakthrough in engineering human and animal genes, state media reported. Dr Han Chunyu and his team at Hebei University of Science and Technology said in May that they had developed a new gene editor called NgAgo that was more efficient and effective than the commonly used one, CRISPR. Science’s rising stars: China’s researchers make big leaps in contributions to top journals Despite initial reports of success by other scientists at replicating the methods of Han’s team, in recent weeks some have started to question whether its findings can be reproduced. Citing a journal spokesman, Xinhua said the publication had been contacted by some researchers who claimed they could not repeat the experiment. The spokesman said Nature Biotechnology would look into the matter, adding that authors must abide by its rules and provide data, codes and experiment procedures to readers in a timely manner. The university said Han would “use appropriate ways” to publicly verify his team’s findings within a month in the presence of a third party, People’s Daily news app reported. The South China Morning Post was unable to reach Han. In May, a poorly funded Chinese research team had announced a huge breakthrough: NgAgo, a new tool for transforming genes. The news led some people to suggest it could become a candidate for a Nobel Prize. Soon, several laboratories in Europe, China and Australia reported on social media that they had repeated the experiment carried out by Han and his team. Han’s findings appeared to herald the dawn of a biotechnology revolution – being able to reprogram genes at will, which could solve problems like cancer and ageing. However, last week an Australian team that had repeated – and originally praised – Han’s work did an about-face and called the experiment “irreproducible and pointless”. Dr Gaetan Burgioof the Australian National University said they had misinterpreted the initial results, and that a more in-depth investigation showed the proposed tool could not change the genes of a mammal at all. “I have found strictly no evidence” of NgAgo’s effectiveness, he wrote in a longTwitter post on Friday. China, US race to develop ‘gene editing’ technology that could, if approved, revolutionise medicine Burgio’s comments were retweeted by Professor Lluis Montoliu of the National Centre of Biotechnology in Madrid, who added on Saturday: “In the light of what we know today I’m dropping all NgAgo projects and recommend everyone to do the same to avoid wasting resources.” Han, 42, has said he would not respond to the debate on social media. He told the Science and Technology Daily , a newspaper run by the Ministry of Science and Technology, on Sunday that he would continue his research and refine the team’s methods until a formal paper could be published in a peer-reviewed journal to challenge or support his findings. So why did Han’s new method generate such controversy, and why should the rest of us care about a technical debate between molecular biologists? The problem stems from CRISPR, currently the most popular genome-editing tool used by scientists to help create new species and cure diseases. The CRISPR uses a mechanism in the immune system to precisely cut or splice various sections of genes, but it has its limitations: it cannot directly target DNA – the material found in all living organisms that carries genetic information. However, Han claims his method uses NgAgo, a special bacteria that can directly edit DNA with extremely high accuracy. This method was first proposed by European scientists several years ago, but at the time the NgAgo bacteria lived only at a temperature of 50 degrees Celsius or more – which is intolerable to most living creatures. However, the work of Han’s team, published in May in Nature Biotechnology , developed a new strain of the NgAgo bacteria that can be used at room temperature – opening the door to almost unlimited applications. An editor at a major life-science research journal said it was too early to draw a conclusion on the effectiveness of NgAgo. “Both the comments of support and criticism [were published] on social media, instead of in peer-reviewed journals,” the editor said.