Gene therapy can be performed safely in the human salivary gland, according to scientists at the National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health. This finding comes from the first-ever safety, or Phase I, clinical study of gene therapy in a human salivary gland. Its results, published this week in the Proceedings of the National Academy of Sciences, also show that the transferred gene, Aquaporin-1, has great potential to help head and neck cancer survivors who battle with chronic dry mouth. Aquaporin-1 encodes a protein that naturally forms pore-like water channels in the membranes of cells to help move fluid, such as occurs when salivary gland cells secrete saliva into the mouth.