Expression of ED-A correlates specifically with myofibroblasts in dcSSc skin. (a,c) Serial cryosections were stained with antibodies against ED-A FN and (b,d) α-SMA. Both ED-A FN ((a,c) arrows) and α-SMA+ve myofibroblasts ((b,d) arrows) were predominant in the lower reticular dermis of dcSSc skin. Note the absence of ED-A FN ((a) white arrow) and α-SMA+ve myofibroblasts ((b) white arrow) in the papillary dermis. In addition, immunostaining for ED-A FN was also detected in the wall of microvessels ((c) inset, arrowheads) correspondingly containing α-SMA-expressing pericytes ((d) inset, arrowheads). Original magnification (a,b) × 10, (c,d) × 20, inset (c,d) × 40. α-SMA, alpha smooth muscle actin; dcSSc, diffuse cutaneous systemic sclerosis; ED-A FN, ED-A splice variant of fibronectin.