COL3A1 and aortic stenosis: In support of this possibility, our previous findings in patients with AS [29] demonstrate that, in the LV, expression of genes encoding fibrosis-related markers (Col1α1, Col3α1, and fibronectin) directly correlates with the expression of Smad-2 (a major effector of TGF-β1 signaling) in men with AS but not in women with AS.