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The Genotype-Tissue Expression Project (GTEx)


Thank you for your interest in the GTEx project. The generosity of donors and donor families make this project possible. The goal of GTEX is to increase our understanding of how changes in genes contribute to common human diseases. This knowledge will improve health care for future generations.

GTEx will create information that will be useful to many researchers, studying many different diseases. The gift of your tissue or your loved one's tissue may lead to research which could help improve treatment for many people in the future.

There are two types of donor groups that participate in the GTEx project: 1) organ and tissue donors, and 2) surgical donors.

  • Organ and tissue donors include individuals who have agreed to donate organs (like kidneys, heart, and liver) and/or tissues (like bone and cornea) for use as medical transplants after they died. Family members may also make the decision to give consent for organ or tissue donation after their loved one has passed on. These donors or their family members have the opportunity to indicate whether any organs or tissues ineligible for transplants may be donated to benefit research studies like GTEx. Donating to GTEx would not interfere with the use of the organ or tissues for transplantation, which takes priority. Compared to surgical donors, many more types of tissues can be obtained for research studies from organ and tissue donors. People who may not qualify to donate organs or tissue for transplants may still qualify to donate tissues to GTEx for research.
  • Surgical donors include people who undergo certain kinds of surgery. If a surgery patient agrees ahead of time, tiny amounts of tissue removed during surgery, such as fat, skin, or muscle, can be donated for use in the GTEx project. Only tissue which needs to be removed for medical reasons can be donated to the GTEx project.  Donating to the GTEx project will not cause any additional tissue to be removed.

GTEx Findings

It has been said that someone has "good genes" when they are particularly healthy, but what does that mean?  How does understanding of genetics translate into better health?  NIH designed the Genotype Tissue Expression (GTEx) project to start to answer this question. The project is looking at the differences in people's genes.

Genes are made up of DNA and DNA is made up of different pieces too. One of GTEx's goals is to identify the pieces of DNA that control how genes behave. These pieces of DNA are called expression quantitative trait loci or eQTLs. These eQTLs control the behavior of genes like a thermostat regulates the temperature of a home. GTEx studies found that the number of eQTLs varies from person to person and from tissue to tissue. Researchers also discovered eQTLs act in different ways. Some eQTLs may affect a set of genes in one tissue, while other eQTLs affect genes in many tissues.

The GTEx consortium has also built an eQTL web-browser ( to help visualize and discover new relationships between genes and the DNA that affects them. This website provides a resource for the many researchers who are exploring the human genome. Understanding how the eQTLs change gene behavior in different tissues can help us understand how diseases develop in people. This knowledge, in turn, may help us develop new therapies and treatments, improving our health overall.

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Last Updated: January 7, 2016