In his research on patients with RA, he proposed that the surface expression of the adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) and the intracellular localization of the enzyme UDPGD were the two best-defined differences that distinguished intimal fibroblasts from subintimal fibroblasts as well as fibroblasts from other sources. Here, VCAM1 is linked to rheumatoid arthritis.