TGFB1 and systemic sclerosis: Both PRO-C3 and PRO-C6 are upregulated in the SiaJ model and in SSc and IPF patients, while the fibrotic profile in SiaJ is growth factor dependent: as both TGF-β1 and PDGF-AB are suspected to be involved in the disease pathogenesis, we speculate that combining the growth factors would give an even more patient-like response.