MARK inhibition facilitates cell invasion. (A) Western blot of overexpression of DN-MARK3 in TKL2 cells shows no effect on AMPK phosphorylation. pACC, phosphorylated acetyl-CoA carboxylase. (B) Quantification of Western blot data (n = 3) in A is shown as means ± SEM. **, P < 0.01; ***, P < 0.001 by two-tailed unpaired t test. (C) DN-MARK3 enhances spheroid invasion into 4 mg/ml 3D collagen. Cells were stained with Alexa Fluor 568–phalloidin to label actin. Bar, 100 µm. (D) Quantification of data in C is shown as means ± SEM. (day 0–3: null, n = 14; addback, n = 9; addback + DN-MARK3, n = 22.) **, P < 0.01; ***, P < 0.001 by one-way analysis of variance (ANOVA) by Dunnett’s post-test, as compared with addback.