VCAM1 and rheumatoid arthritis: Increases in VCAM1 expression in macrophages, fibroblasts and endothelial cells have been reported in rheumatoid arthritis,25 while Vcam1 expression in murine osteoblasts is important for cellular adhesion and activation of osteoblasts to binding partners in bones, which are required for maintaining the signals regulating the balance between bone formation and bone resorption.26