COL4A1 and cancer: Western blot (WB) analysis revealed that cell lines expressing COL4A1/Col4a1, COL4A2/Col4a2 and COL4A5/Col4a5 combination expressed relatively more vimentin (intermediate filament characteristic of mesenchymal cells) than A549 cells which expressed abundant E-cadherin known to stabilize epithelial organization (Figure 1A), suggesting that cancer cell lines expressing α1α2α5(IV) chain combination have underwent EMT [17].