Thanks to identical twins, we might be able to detect breast cancer before it even develops

Scientists practically drool over identical twins and their shared DNA, especially when one twin develops a major, and possibly genetically related illness, and the other does not. Identical twins can help unlock medical mysteries that might otherwise go unsolved.
The results of a recent study on breast cancer can help the rest of us appreciate the scientific fever over identical twins and their potential contributions.
This is a big one.
The study -- led by Manel Esteller, director of the Cancer Epigenetics and Biology Program at the Bellvitge Biomedical Research Institute (IDIBELL), Professor of Genetics at the University of Barcelona and ICREA researcher -- has helped researchers identify a genetic change that occurs in those who will later develop breast cancer.
This information could lead to new blood tests that help doctors identify breast cancer victims long before their cancers actually develop. It could lead to new drugs that more efficiently target tumors and that prevent breast cancer in the first place.
It all goes back to epigenetics.
All DNA is influenced by environment.
Chemical signals received by DNA can trigger certain changes, turning genes off and on like a light switch. That's the theory behind epigenetics. It's why some pairs of identical twins have clear physical differences, like height or moles or head shape. It explains lower immunity in one twin than in another. It shows why some will develop certain genetic diseases while their twins do not.
In this case, researchers found that twins with breast cancer had "a pathological gain of methylation in the DOK7 gene" years before their cancer was clinically diagnosed, according to Dr Esteller in an article on the institute's website.

The next step for the researchers will be knowing the exact function of the DOK7 gene. "We believe it is a regulator of tyrosine kinases, an antitumor drug target already used for the treatment of breast cancer. If DOK7 performs this function, new studies to test drugs with tumour chemopreventive effects in breast cancer could be planned in the future," he concludes.

In simpler terms, scientists believe that particular gene is a regulator of a drug already used to fight tumors. If that proves true, the information could lead to big changes in the way we diagnose, treat and prevent breast cancer.  A simple blood test could tell women (And men. Let's not forget they can have breast cancer too.) whether they will develop the disease in the near future.
All thanks to 36 sets of selfless identical twins.