VEGF at low concentration (1–10 ng/ml) is a potent chemoattractant for HIMEC migration in vitro. Effect of VEGF on HIMEC migration assessed by a Transwell chemotaxis assay. HIMEC migrating across fibronectin-coated polycarbonate filters (pore size, 8 μm) were quantified using modified Wright's stain (Diff-Quik) and bright field microscopy. Left panel; VEGF (1–10 ng/ml) elicits strong chemotactic properties in HIMEC. Note the biphasic dose response, as higher concentrations of VEGF (50 ng/ml and higher) do not result in marked chemotaxis in HIMEC. Right panel; VEGF (10 ng/ml) induced chemotaxis in HIMEC is decreased by specific inhibitors of p38 MAPK (SB203580), CsA and FK506 but not Rapamycin. As shown in the right panel, VEGF acts as a potent chemoattractant for HIMEC. This chemotactic response was potently diminished by SB203580 (5 μM), CsA (0.1 μM) and FK506 (50 nM). * = p < 0.05 versus positive control; n.s. = not significant. No VEGF, denotes the negative control while VEGF (10 ng/ml) served as the positive control. All conditions were assessed in triplicate, and data are expressed as mean number of migrated cells per high-power field (200×) ± S.E.