HGF and cancer: It has been reported CAFs enhance the invasion of cancer cells via various mechanisms, such as MMP-mediated ECM degradation and subsequent release of latent growth factors [22]; matrix stiffening through integrin-mediated mechanotransduction and through actomyosin contractility [150, 350]; secretion of soluble factors, including HGF and TGF-β [345, 351, 352]; secretion of exosomes [55]; and direct cell-cell contact [353].