Fibrosis is one of the hallmarks of leiomyomas, where dysregulated ECM plays a crucial role.30, 31 ECM such as collagen, fibronectin, laminins and proteoglycan are overexpressed in ULs, which induces mechanotransduction by integrin activation and increases tissue stiffness by altering bidirectional signalling.31 This evidence concerns the gene FN1 and leiomyoma.