MMP9 and neoplasm: Correlated with the aforementioned finding, conditioned media from MSCs, TGF-β conditioned MSCs and TGF-β conditioned MSCs + AMD3100 were analyzed by ELISA to detect the expression levels of matrix metalloproteinase (MMP) family members MMP-2 and MMP-9, which can promote tumor cells to invade surrounding tissues and metastasize to distant tissues in a variety of tumors (Fang et al., 2021; Yin et al., 2021).