Depletion of PAK reduces melanoma invasion in vivo. A. Stable reduction of PAK1 and PAK4 in the A-375M2 cell line. B. Diagrammatic representation of the invasive cell movement during the yolk invasion assay, including: (i) Tumour intravasation into blood vessels; (ii) Transportation in the blood vessels; and (iii) cells lodge in tail vessels and extravasate. C. Phase contrast and fluorescent images of zebrafish embryos at 4 dpi for embryos injected with control, PAK1 and PAK4 depleted cells (C). Red stars indicate cell mass in yolk sac (original injection site). White arrows indicate tail invasion of GFP labelled cells. Scale bar = 500μm. D. High magnification of tail invasion E. The percentage of embryos with cell tail invasion. Significance was calculated compared to control shRNA cells. Data are the mean values ± S.E.M., over at least 3 independent experiments; n = total number of embryos, *= P 00< 0.05.