SERPINE1 and systemic sclerosis: Other data more strongly support TGF-β as driving the second step, transition of SFRP2hiPRSS23+WIF1− fibroblasts to myofibroblasts, as many of the genes upregulated in myofibroblasts are known TGF-β targets and are in a cluster of genes downregulated in the skin of SSc patients after treatment with anti-TGF-β/fresolimumab treatment of SSc patients, such as THBS1, COMP, SERPINE1, COL10A1, CTGF, and MATN3 (ref. 51).