We are concerned about the prospect of China becoming a world leader in research involving non-human primates, given the country's comparatively weak regulatory system and ethical framework (see Nature 532, 281; 2016 and Nature 532, 300–302; 2016).

China's relative freedom from the “ethical pressure” you mention makes it attractive to researchers working on primates. But animal studies that could fail the harm–benefit evaluation in many Western regulatory systems should not be allowed — or actively encouraged — to take place elsewhere. Far from putting researchers under negative ethical pressure, the project-authorization process in the European Union was set up with full input from scientists and is often held up (by them) as an appropriate safeguard to promote good quality, ethically conducted science and good animal welfare (Nature 521, 7; 2015). You cannot have it both ways.

Rather than exploiting weaker animal-research regulations, we argue that more effort should be invested in developing and validating alternative technologies to avoid or reduce the use of non-human primates.