Another example is transforming growth factor (TGF)‐β1, a crucial member of the TGF family, which induces epithelial‐mesenchymal transition (EMT) in tumor progression and metastasis.[106] A tumoral ECM‐mimicking matrix was made using LbL films with controllable stiffness, with dopamine used to immobilize TGF‐β1 with a high efficiency of ≈90%.[107] The stiff matrix with immobilized TGF‐β1 (i‐TGF) was the only condition able to induce mesenchymal phenotype and promote the EMT progression of hepatocellular carcinoma cells. Here, TGFB1 is linked to hepatocellular carcinoma.