The researchers say their discovery has implications for the treatment of cancer, lymphatic disorders and other diseases.

The team, led by Professor Peter Koopman and Dr. Mathias Fran?§ois found that a single gene - Sox18 - triggers the development of the lymphatic vessels.

Professor Koopman says the rate at which new lymphatic vessels can form is thought to be one of the key factors in determining how quickly a tumour can spread and how severely a patient will be affected by cancer.

He says the lymphatic vessels also play a central role in maintaining fluid balance in the body and carrying infection-fighting white blood cells and the more knowledge gained about the lymphatic system the more insights and possible therapies for a range of diseases will be available.

The discovery came about in research with mice where Sox18 had been inactivated with the result that the development of the lymphatic vessels was massively disrupted.

Professor Koopman says the suspicion that Sox18 might play a critical role in lymphatic vessel formation came when mice with one inactivated copy of the gene displayed similar symptoms to humans with a genetic condition that affects the lymphatic system, known as lymphatic tissue hyperplasia (HLT).

Professor Koopman says it transpired however that Sox18 had a much more important role than first thought and is in fact the master controller of lymphatic vessel development.

The team now plan to focus on finding genes regulated by Sox18 and determining how this regulation occurs, which may suggest ways of promoting or preventing lymphatic vessel formation.

The researchers say once it is known how to prevent lymphatic vessels from forming, the ability to halt the spread of tumours through the body will be a lot closer and knowing how to stimulate the formation of these vessels, might make the treatment of diseases such as lymphedema a possibility.

Lymphedema occurs when the lymphatic vasculature is impaired, causing a build-up of fluid in part of the body, which leads to painful and dangerous swelling of that body part, and, if left untreated, deformity.

The discovery which was the result of three years of research by an international team of scientists from Australia, Italy and Hong Kong, led by UQ, was supported by the Australian Cancer Research Foundation, the National Health and Medical Research Council of Australia, the Heart Foundation of Australia, and the Australian Research Council.

The study is published in the science journal Nature.