Haptotaxis does not require MAP4 or microtubules. (A) Western blots showing overexpression of active MAP4 in LKB498 cells. exp., exposure. (B and C) Active MAP4 does not affect haptotaxis of LKB498 cells in 2D (B) and 3D (C). (addback, n = 51; GFP-MAP4-S914A/S1046A [SA], n = 48.) (D) Nocodazole depolymerizes microtubules in LKB498 cells. Bar, 20 µm. (E) Nocodazole (noc) treatment of LKB498 LKB1 addback cells has no effect on haptotaxis. (640 nM, n = 37; 10.24 µM, n = 35.) (F and G) Washing of nocodazole alone (F) does not block haptotaxis (before wash in, n = 69; wash in, n = 51) but together with MARK inhibitor (G) blocks haptotaxis in IA32 fibroblasts. (before wash in, n = 155; wash in, n = 107.) All haptotaxis data are shown as mean ± 95% confidence intervals. **, P < 0.01; ***, P < 0.001 by two-tailed unpaired t test. v, velocity; D/T, displacement (D) over the total path length (T).