MMP9 and lung cancer: To determine whether CAFs induced the EMT phenotype in the abovementioned lung cancer cell lines, we measured the levels of the epithelial marker E-cadherin (CDH1), the mesenchymal marker vimentin (VIM), and matrix metalloproteinase 2 (MMP2) and MMP9 in A549, H1299, SPC-a-1 and LTEP-a-2 cells co-cultured with CAFs.