Millions of computer users are being invited to contribute to cancer research via an interactive website.
The "citizen science" project from Cancer Research UK is the first of its kind in the world. It is designed to speed up the rate at which molecules can be identified in cancer cells that may predict how a patient responds to treatment.
The Cell Slider website presents real images of tumour samples and operates in a similar way to the card game snap. Users are first guided through a tutorial which explains which cells to analyse and which ones to ignore.
Once cancer cells have been identified by their irregular shape, users are asked to record how many have been stained yellow and how bright the colour is. They do this by clicking on another image that most closely matches the sample they are viewing. The information is fed back to researchers who look for correlations between cell types and treatment responses.
Professor Paul Pharoah, from Cambridge University, who helped develop Cell Slider, said: "We're really excited to be involved in this world-first project and we're extremely eager to see what this can do for our research in the future.
"There is information that can transform cancer treatments buried in our data - we just need the manpower to unlock them. We've turned our data into something that can be accessed by anyone - you don't have to be a scientist to carry out this type of cancer research.
"If we can get millions of people on Cell Slider, we hope to condense what normally takes years of research into months."
Initially, the project will focus on breast cancer samples. The yellow stain indicates levels of a protein found on the surface of breast cancer cells called the oestrogen receptor (ER).
It is this molecule that allows the hormone oestrogen to stimulate cancer growth in the majority of cases. Only women with high ER levels can be treated with hormone therapies, such as tamoxifen, which blocks the receptor.
To test how accurate the programme is, scientists will link samples flagged up by Cell Slider players to anonymised data on treatment and survival.
If the pilot trial is successful, Cell Slider will be expanded to include samples with patients with other types of cancers, and colours representing other biological markers. Each image of a tumour sample will be analysed by several people to ensure that accidental clicks are discounted.
Prof Pharoah said: "Eventually, we hope to be able to identify different types of breast, and other, cancers and find out how these different types respond to different treatments. This will enable us to match up women with the right cancer drugs based on their tumour type.
"We hoped that this personalised medicine approach would be a reality in years to come, but this computer programme could make this a reality sooner than any of us had imagined possible."
Professor Andrew Hanby, another member of the team from the University of Leeds, said: "We're being held back by how quickly we can process information on tumour samples. Computers can only go so far - they can pick up obvious trends but only the human eye can spot subtleties that have, in the past, led to important serendipitous discoveries.
"Cell Slider makes our data so accessible - it's not just for scientists and computer geeks - everyone can play their part in curing cancer from the comfort of their own homes."
Dr Harpal Kumar, chief executive of Cancer Research UK, said: "Getting the public involved in research - or citizen science - recently helped astronomers discover a completely new galaxy and many new planets.
"We're asking people across the world to help us save lives from cancer by giving just a few minutes of their time to log onto Cell Slider and help our scientists unearth information that would usually take years to discover."
Science minister David Willetts called the initiative "really exciting and innovative".
He added: "I saw the website on a recent visit to the Birmingham Cancer Research UK Centre and was impressed by how easy it is to use and how much it will speed up vital research.
"It's another example of how the UK is one step ahead of the rest of the world in coming up with creative ways to solve scientific problems."