FAK, Phosphorylation of FAK Tyr397 and SRC in glioma cells depends on substrate stiffness. Western blot analysis (a) and densitometry of (b) FAK, (c) phosphorylation of FAK Tyr397 and (d) SRC levels in lysates from U251 cells cultured on bulk stiff, bulk soft and flat durotactic, the Ctrl is the Petri dish. Quantified values hown in the graph (n ≥ 3). FAK, P-FAK and Src expression levels were normalized to the β-actin. Immunofluorescence staining merge of phalloidin, vinculin and HOESCHT showing actin cytoskeleton organization of U251 cells treated with inhibitors on flat substrates with (e) blebbistatin (f) ROCK Y-27632, and (g) Cyto D and micropatterned durotactic lines with (h) blebbistatin (i) ROCK Y-27632, and (j) Cyto. D. Scale bar 100 µm.