The 2015 Nobel Prize in Chemistry has been awarded for discoveries in DNA repair.
Tomas Lindahl and Paul Modrich and Aziz Sancar were named as the winners on Wednesday morning at a news conference in Stockholm, Sweden.
Their work uncovered the mechanisms used by cells to repair damaged DNA - a fundamental process in living cells and important in cancer.
Prof Lindahl is Swedish, but has worked in the UK for more than three decades.
The prize money of eight million Swedish kronor (£634,000; $970,000) will be shared among the winners.
"It was a surprise. I know that over the years I've occasionally been considered for a prize, but so have hundreds of other people. I feel lucky and proud to be selected today," Tomas Lindahl, from the UK's Francis Crick Institute, told journalists.
Claes Gustafsson, from the Nobel Committee, said the recipients had "explained the processes at the molecular level that guard the integrity of our genomes".
Monitoring and repair
DNA is open to an onslaught of different phenomena that can generate defects in our genomes.
UV radiation and molecules known as free radicals can cause damage. Furthermore, defects can arise when DNA is copied during cell division - a process that occurs millions of times each day in our bodies.
"Cigarette smoke contains small reactive chemicals, which bind to the DNA and prevent it from being replicated properly - so they are mutagens. And once there is damage in the DNA this can cause diseases including cancer," said Prof Lindahl, who for 20 years ran the Clare Hall laboratories in Hertfordshire - now part of Cancer Research UK.
To address those defects, a host of molecular systems continuously monitor and de-bug our genetic information. The three new laureates mapped in detail how some of these mechanisms worked.