UK researchers digest the fallout from Brexit.

www.thelancet.com Vol 388 July 9, 2016 115 The president of the UK’s Academy of Medical Sciences professor Sir Robert Lechler was candid when it came to his view on the research implications of the UK referendum result: “I think this represents the biggest challenge to the UK’s research sector in living memory.” The referendum on June 23, in which voters took the momentous decision to leave the European Union (EU), was the most divisive to date, with 52% of people voting to leave versus 48% voting to remain. The mood of those who wanted to remain is now shifting back and forth between deep disappointment (and visions of the potential bleak future for the UK) and attempts at optimism. Some remain voters think it is important to start seeing the result as a challenge that needs to be quickly engaged with. As more days pass since the vote, the list of issues posed for the UK is getting longer and longer. Experts think that both the National Health Service (NHS) and UK science could be hit hard. As the remain camp considers its next steps, with some desperately looking for ways to reverse an exit from the EU, others think the most constructive thing to do is to take a deep breath, put heads together, and focus on protecting the UK’s muchcelebrated NHS and scientifi c research environment. The biggest problem is that until negotiations take place about exiting the EU, everyone is still in the dark about what it could mean for the UK.