GJA1-20k rescued microtubule track density in C33A cells with GJA1 knockdown. (A) Representative images visualizing microtubule movement tracked by EB1 over one-minute time-lapse imaging, interval = 1s. Scale bar = 5 µm. (B) Quantifications of microtubule track local thickness (n = 35, 27, 24, and 23 cells from Ctrl siRNA, GJA1 siRNA, GJA1 siRNA + GST, and GJA1 siRNA + GJA1-20k, respectively, from three independent experimental repeats). (C) Representative images of C33A cells stained with tubulin Tracker Deep Red. Scale bar = 10 µm. (D) Quantifications of total tubulin density by measuring areas occupied with tubulin Tracker divided by cell areas (n = 92, 64, 83, and 84 cells from Ctrl siRNA, GJA1 siRNA, GJA1 siRNA + GST, and GJA1 siRNA + GJA1-20k, respectively, from three independent experimental repeats). Data are presented by mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001 with the Kruskal–Wallis test with Dunn’s post hoc test.