MMP9 and neoplasm: Moreover, studies have reported that tumor constituent cells regulate the biomechanical properties of the ECM, decreases the ECM stiffness by increasing the matrix metalloproteinase (MMPs) such as MMP2, MMP9, MMP13, and MMP14 enabling them to metastasize to distant tissues (Northcott et al. 2018; Li and Wang 2020).