In addition, fibronectin impacts the tensile strength in smooth muscle cells 42 and can increase cytoskeletal organization and mechanical tension generation by cells.43 In leiomyomas, mechanotransduction appears to regulate Smad3 activity 44; indeed, in other smooth muscle cells, Smad3 activation correlated with fibronectin polymerization. This evidence concerns the gene FN1 and leiomyoma.