Perturbation of MT growth or shortening promotes HUVEC branching and inhibits rapid directional migration. (A) Immunolocalization of MTs and fluorescent phalloidin staining of actin in HUVECs cultured on collagen-coated glass, or stiff (8.7 kPa) or soft (0.7 kPa) compliant ECMs. Samples were treated with DMSO (control), 20 µM nocodazole (Noc.), or 20 µM taxol for 90 min. Bars, 20 µm. (B) Analysis of the effects of the treatments in A on cell branch frequency and length. (C) Analysis of the effects of the treatments in A on cell migration velocity and distance to origin. *, P < 0.05 comparing compliance versus compliance + drug. **, P < 0.05 compared with glass (one-way ANOVA). Error bars indicate standard deviation.