IL17A and systemic sclerosis: To elucidate the roles of the ERK1/2 and p38 MAPK signaling pathways in endothelial cell inflammation, ERK1/2 inhibitor (PD98059) and p38-MAPK inhibitor (SB203580) were used to treat HUVECs in the presence of IL-17A or serum from SSc patients and healthy controls.