Working Title: Hydrogen Sulfide - Biochemical and Biological Considerations

In the past years biomedical research has recognized hydrogen sulfide (H2S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gasotransmiter with paramount roles in health and disease. Current research is focused on several aspects of H2S biology such as the biochemical pathways that generate the compound, functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present editorial addresses the knowledge we have to date on H2S production and its biological roles in the general human environment with a special focus on the oral cavity.