<page_title> List of Nobel laureates in Physiology or Medicine </page_title> <section_title> Laureates </section_title> <table> <cell> 1998 <col_header> Year </col_header> </cell> <cell> "for their discoveries concerning nitric oxide as a signalling molecule in the cardiovascular system" <col_header> Rationale </col_header> </cell> </table>
The 1998 Nobel Prize in Physiology or Medicine was awarded for discovering nitric oxide's role as a cardiovascular signalling molecule.