Used in research settings as a potent and selective inhibitor of the enzyme dihydroorotate dehydrogenase (DHODH), GSK2643943A is primarily investigated for its antiviral properties. It has shown activity against a range of RNA viruses by disrupting pyrimidine biosynthesis, which is critical for viral replication. Studies have explored its potential in inhibiting viruses such as respiratory syncytial virus (RSV) and other related pathogens. Due to its mechanism of action, it serves as a tool compound in antiviral drug development and host-targeted therapy research. Not intended for clinical use, it remains valuable in understanding viral dependence on host metabolic pathways.