SMAD2 and Thrombophlebitis: Other authors, after observing differences in TGF-β1 expression/activity (as well as in some of its signaling components, such as TGF-βR2 and Smad2/3) among control veins, varicose veins and varicose veins complicated by thrombophlebitis, proposed that thrombophlebitis accelerates TGF-β1 activation and its signaling cascade in the varicose vein wall, which may have a role in the local inflammatory process [113].