Split and merged confocal images of a representative venous valve and vein wall. (A) 4′,6-diamidino-2-phenylindole hydrochloride (blue) binds to DNA; (B) VWF (white); (C) EPCR (red); (D) TM (green); (E) merged image (the overlap of red and green fluorophores is perceived as yellow); (F) higher magnification of the merged image of the valve sinus and (G) higher magnification of the merged image of the vein lumenal wall just distal to the valve images in A-D. (F-G) Images were inserted to include an extended area of both the valvular sinus endothelium and the nonvalvular endothelium distal to the valve (see supplemental data). White arrow in panel E indicates vein luminal endothelium; and white asterisk, valve sinus. Scale bars indicate 100 μm (A-E) and 50 μm (F-G).