IL17A and systemic lupus erythematosus: Our previous study showed that Th17 cells are expanded in systemic lupus erythematosus (SLE) patients, and Th17 cell-derived IL-17 is related to recruitment of inflammatory cells to vascular endothelial cells[12]; however, the role of Th17 cells and IL-17 in the fibrosis of SSc is not clear.