Hundreds of North East 'babies' who became involved in a health study nearly 60 years ago are being urged to help in the fight against cancer.
Experts at Newcastle University have been following the lives of 1,000 people born in May and June 1947.
They are known as 'red spot babies' because of the way doctors marked their medical files.
Now 300 of the women are being urged to come forward in a study aimed at tackling breast cancer.
Over the years the 'red spot babies' have undergone a battery of tests to build up a picture of what determines good health.
Dr Mark Pearce, director of the 1,000 Family Study, said: "The women who took part in the original survey are being called on again.
"On top of this, we are examining how oestrogen exposure throughout their life has affected them now they are in their late 50s.
"We're trying to establish any link between all these factors and the women's breast tissue density."
Breast tissue density is used as a marker for breast cancer risk.
High-density breast tissue is associated with an increased risk of breast cancer so the experts are now planning to study this.
The original experiment was established during the 40s because of concerns over high numbers of children dying before their first birthday.