Researchers have been given approval to carry out a large clinical trial of a new treatment for patients with an aggressive type of brain tumour.
The trial involves injecting a virus into the tumour
There is currently no cure for glioma but experts believe that gene therapy could make a real difference.
The first patient to receive the treatment seven years ago is still alive, despite initially being told he had just four months to live.
The trial will be carried out by researchers in Glasgow.
The new treatment involves injecting Herpes simplex virus into the brain tumours of glioma patients.
The virus is modified so that it targets and kills cancerous cells but leaves normal brain cells undamaged.
Gene therapy is a relatively new form of experimental treatment and must be tightly regulated.
The Gene Therapy Advisory Committee had to approve the research, ensuring that it met the highest standards, was ethically and scientifically sound and that patient welfare was paramount.
Professor Norman Nevin, chairman of the Gene Therapy Advisory Committee (GTAC) said: "Gene therapy offers enormous potential to patients with conditions such as cancer and the UK has been at the forefront of research in this area.
"This new treatment could offer hope to patients with malignant gliomas.
"After carefully considering the risks and benefits to patients, the committee has decided to give the go ahead to further trials so that we can demonstrate the effectiveness of this new therapy."
The trial is being led by Moira Brown, Professor of Neurovirology at University of Glasgow Hospitals NHS Trust.
The GTAC has approved 90 gene therapy clinical trials since 1993, involving more than 700 patients.
The majority of trials were for the treatment of cancer but other studies targeted inherited disorders such as Cystic Fibrosis and Hurler's Syndrome, infectious diseases such as HIV infection and vascular disease.