ICAM1 and systemic sclerosis: ICAM-1 (CD54) and VCAM-1 (CD106), both induced by pro-inflammatory cytokines such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α in response to endothelial damage, and both mediating firm leukocyte adhesion and transmigration across the vascular endothelium, have been intensively studied in SSc [12,28].