The case for a pivotal role of gap junctions in the EDHF phenomenon has strengthened. Gap junction plaques are most abundant in small resistance arteries and their distribution is proportional to the magnitude of the EDHF-mediated response. These topographical data have been extrapolated to argue for a direct link between gap junctions and EDHF. Furthermore, murine knockout models provide direct evidence for a role of gap junctions and specific connexins in the control of vascular tone.