TGFB1 and systemic sclerosis: The top bin also includes components of the extracellular matrix, including the heparan sulfate proteoglycan 2 (gene name HSPG2) that was previously shown to be implicated in fibrotic processes (45, 46, 47) including SSc-associated fibrosis (48), wound healing (49, 50) and TGF-β signaling (51, 52).