From nuclear bombs to nuclear genomes

In August 2025, a US-based startup announced plans to bring human germline genome editing out of the shadows and into the spotlight. The venture is led by entrepreneur Cathy Tie, ex-wife of He Jiankui – the Chinese scientist who in 2018 was responsible for the birth of the world's first CRISPR-edited babies, an experiment that drew global condemnation and landed him in prison. He Jiankui is currently attempting a comeback in Texas, while Cathy Tie has launched her own effort on US soil and branded it the Manhattan Project.

Her co-founder – Dr Eriona Hysolli – trained in Professor George Church's laboratory at Harvard, coauthored a 2018 review with him on the future of DNA design, and was part of a 2022 study exploring multiplex genome recoding. Until recently, Dr Hysolli headed biological sciences at Colossal Biosciences, working on 'resurrection' projects such as creating a woolly mammoth proxy. Now, she has turned her attention from rewriting animal genomes to rewriting human inheritance.

The name is no accident. The original Manhattan Project was the Second World War programme that developed the atomic bomb, a technological triumph that also unleashed devastating consequences. By appropriating this title, the new company casts itself as leading a similarly world-changing scientific venture. But the resonance is double-edged – is germline editing to be humanity's salvation from genetic disease, or its own form of Pandora's box?

A controversial history

The announcement comes against the backdrop of one of the most contentious episodes in modern science. In 2018, He Jiankui shocked the world by announcing the birth of twin girls, 'Lulu and Nana', whose genomes had been edited with CRISPR (see BioNews 977). The experiment was universally condemned as premature, reckless, and unethical. He Jiankui was sentenced to three years in prison (see BioNews 1029), and the episode prompted calls for an international moratorium on heritable human genome editing (see BioNews 991).

Seven years on, genome editing methods have become more precise, CRISPR-based therapies are advancing through clinical trials, and somatic gene therapies have entered mainstream medicine. NPR's coverage of the Manhattan Project notes that some scientists and investors now believe the time is right for renewed exploration of germline editing, though many remain deeply sceptical.

The Manhattan Project's principles – and pitfalls

The company's public statements attempt to reassure. 'Our sole mission is to prevent and ultimately eradicate devastating inherited diseases,' their FAQ declares. 'Our focus is exclusively on health and medical applications.' This framing positions embryo editing as a form of public health intervention, and yet critics note that most inherited diseases are already avoidable through preimplantation genetic testing, which avoids altering the germline.

On the spectre of enhancement, the company insists: 'Our work is strictly focused on correcting gene mutations that cause severe diseases.... Our ethical framework is built around the principle of healing and reducing suffering.' Still, some investors – vocal advocates for enhancement – complicate this neat boundary, fuelling concern that the rhetoric of therapy could slide into eugenics.

The use of embryos is another flashpoint. In response to critics who equate research with 'killing babies', the FAQ counters: 'No, an early human embryo is not a fetus or a developing baby in a womb.... These embryos would otherwise be unusable or discarded.' The company also points to embryo models derived from stem cells as a way of reducing reliance on IVF embryos. Yet the assertion that an embryo 'is not a baby' sidesteps deeply held moral disagreements about the embryo's status.

Affordability is addressed in similarly aspirational terms: 'Our mission is to democratise the treatment to anyone in need… preventing genetic disease should be a standard part of healthcare and available to anyone consenting.' Whether a high-cost, cutting-edge biotechnology can ever be truly 'democratised' remains an open question.

Finally, on calls for a moratorium, the FAQ is unequivocal: 'We believe a moratorium would be counterproductive.... A ban in the USA would not stop the research; it would simply push it to countries with less regulatory oversight.' This reflects a common Silicon Valley argument – that scientific progress is inevitable, so regulation should accommodate it rather than resist it. But critics warn that this framing risks normalising premature experimentation, with consequences carried by future generations.

Regulation and the global picture

At present, US federal law prohibits the Food and Drug Administration from considering applications involving heritable genome editing. The Manhattan Project calls for revisiting restrictions such as the Dickey-Wicker and Aderholt amendments.

Globally, however, the landscape remains unsettled. In May 2024, South Africa became the first country to issue national health research ethics guidelines that explicitly addressed heritable human genome editing (HHGE). The initial version of the guidelines suggested that such interventions could, in principle, be justified if there were a 'clear and compelling scientific and medical rationale,' particularly in the prevention of serious disease (see BioNews 1265).

While debate continues over whether this amounts to full legalisation, it signals a remarkable divergence from the prevailing international consensus that germline editing remains unacceptable. This provoked intense national and international criticism, with concerns that the guidelines risked opening the door to 'designer babies' and contained contradictory provisions.

In response, South Africa's National Health Research Ethics Council released a revised version of the guidelines that removed the HHGE section entirely, replacing it with a commitment to further national stakeholder engagement. The revision emphasises that given ongoing scientific and ethical debates, any future position must be informed by broad, multidisciplinary consultation.

While South Africa's National Health Act already prohibits reproductive manipulation of human gametes and embryos, the brief inclusion and subsequent withdrawal of HHGE provisions underscores both the regulatory ambiguity and the rapidly shifting global terrain.

Looking ahead

The (new) Manhattan Project has reignited a dormant but inevitable debate – should humanity use its growing mastery of the genome not only to cure disease, but also to reshape inheritance itself? The Project emphasises compassion and prevention while glossing over pressing questions of equity, governance and the blurred line between therapy and enhancement.

The company's choice of name could not be more telling. Like its wartime predecessor, this Manhattan Project aspires to change the course of history through science. The question society must now answer is not only whether this endeavour represents salvation from genetic disease, but – more simply – 'Is humanity ready for this?'.