HTRA1 knockdown inhibits cell migration and proliferation of GBM cells in vitro. (A, B) Representative images of transwell assays and cell counting results for LN229 and U251MG cells transfected with HTRA1 siRNAs. Bar = 200 μm. (C, D) Representative images of wound healing assay and migration rates for LN229 and U251MG cells transfected with HTRA1 siRNAs. Bar = 200 μm. (E, F) Representative images of 3D invasion assays and invasion rates for U251MG and GBM#P3 cells transfected with HTRA1 siRNAs. Bar = 100 μm. (G, H) Representative images of western blots and relative expression levels of EMT‐related proteins in lysates prepared from LN229, U251MG and GBM#P3 cells transfected with HTRA1 siRNA. (B, D, F and H), one‐way ANOVA, post hoc Dunnett's test. *P < 0.05; **P < 0.01; ***P < 0.001.