MMP9 and neoplasm: Immunofluorescence results showed that the addition of non-parenchymal cells greatly enhanced the expression of EMT-related molecules (MMP9, vimentin, and TGF-B), tumor-related inflammatory factors (TNF-α, CXCL12, and CXCR4), and neo-angiogenesis-related markers (VEGF, VEGFR2, and HIF-α), which are important factors in the tumor microenvironment for tumor growth and drug resistance (213).