KDR and diabetes mellitus: Expression of KDR (Flk-1, VEGFR-2), the major receptor mediating the proangiogenic VEGF action, was higher in db/db cells, and not modified by rosiglitazone (Figure 3B), while Flt-1 (VEGFR-1) level was affected neither by diabetes nor by rosiglitazone (Figure 3C).