Scientists have been given the go-ahead to set up a mouse library to help disease research.
Mice research will play a "pivotal" role in research
The pan-Europe project aims to produce embryonic stem cells for 20,000 mutated mice to help scientists find out how genes cause conditions such as cancer.
Scientists believe mice will play a "pivotal role" in understanding more, as 99% of human genes are found in the animals.
One area of research on the mice will be why red heads can stand more pain.
The link between red hair and a greater pain threshold was first established eight years ago.
In 2004, a Canadian team identified the gene responsible for the effect - and now scientists across the world are using mice to try to establish why in the hope of developing pain killing drugs.
But it is the potential of mice research to unlock the secrets about a whole range of disease affecting vision, hearing, behaviour and the brain which is most exciting to researchers.
The £9m European Commission-funded mouse library, which will take three years to compile when works starts in 2006, will aim to produce 20,000 mutant mouse stem cells by neutralising the impact of 20,000 of the animal's 25,000 individual genes.
Scientists across the world will then be able to order mutated mice from the EUCOMM programme, instead of having to develop them themselves, to analyse how disease develops.
Most diseases are a combination of environmental and genetic factors.
For some conditions, such as many motor neurone disease, one gene has been identified as the cause, while for others such as cancer and diabetes, the cause is more complex.
But scientists believe by altering the genetic make-up of mice they will be able to work out how genes lead to disease.
Professor Steve Brown, director of the Medical Research Council's mammalian genetics unit and head of one of the two UK teams involved in the project, said it would create a "tremendous resource" for the bio-medical research community.
He said: "We have mapped the human genome - the challenge now is to understand the function of these genes and their role in disease.
"Mice will play a pivotal role [because of their genetic make-up]."
Professor Elizabeth Fisher, who is researching neurodegenerative disease at University College London, said: "Not every laboratory has the resources needed for mutated mice.
"To have this facility available would help many research programmes."
And Professor Ian Jackson, from the Medical Research Council's human genetics unit, said it could save "money and time".