CCL20 and systemic sclerosis: IL-17A can promote collagen secretion of fibroblasts and stimulate the expressions of intercellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), chemokine (C-X-C motif) receptor 4 (CXCR-4) and chemokine (C-C motif) ligand 20 (CCL-20) in vascular endothelial cells, resulting in endothelial inflammation in SSc [14,15].