CTLA4 and systemic sclerosis: In addition, CTLA4-Ig interacts with the costimulatory molecule CD86 on human endothelial cells, masking its expression and modulating the expression of vascular endothelial growth factor receptor (VEGFR)-2 and ICAM-1, two important molecules involved in inflammatory and angiogenic processes that characterize several autoimmune diseases, including SSc [24].