MMP9 and cancer: To further verify the role of EFNA4 and ETS1 in the process of EMT, TGF-β, HGF, FGF, SDF-1, IL-6, IL-32, CCL5, CXCL12, MMP-2, and MMP-9 were selected for correlation analysis with EFNA4 and ETS1, these genes are secreted by cancer-associated fibroblasts (CAFs) and then enable the EMT process.