ICAM1 and systemic sclerosis: Purified IgG from AECA-positive SSc, PAH, or SLE patients is able to upregulate cell expression of various chemoattractant molecules (ICAM-1, VCAM-1, E-selectin, CCL2, or CXCL8), ROS production, interleukins (IL-6, -8) (56–58) and promotes intima hyperplasia and contributes to vascular injury (75).