TGFB1 and systemic sclerosis: This all suggests that the Th17 cells reduce collagen expression via the upregulation of the negative regulator miRNA-129-5p; however, in SSc fibroblasts, the dysregulated TGF-β levels alter the cells’ sensitivity to IL-17, possibly through downregulation of the TGF-β receptors, thus leading to reduced IL-17 stimulation and a decrease in miRNA-129-5p and ultimately leading to enhanced collagen levels.