Fig. 4. ZBP1 localizes to the periphery of cells and reduces motility and orientation towards vessels in living tumors. (A) ZBP1-GFP-expressing cells imaged in vivo using multiphoton microscopy show ZBP1 (green; one cell outlined with dotted line) localized to the periphery of cells and at cell-cell junctions (arrow). Collagen is imaged by second harmonic generated polarized light in the multiphoton microscope (purple, arrowhead). (B) MTLn3 cells transfected with CFP show elongated cell morphology (arrow) and orientation towards vessels (black spaces) in a living tumor. (C) ZBP1-expressing cells show a rounded morphology (arrowhead) along vessels. ZBP1-expressing cells do not polarize in the direction of vessels. Bars, 25 µm. (D) ZBP1 cells are less motile than cells in tumors generated by MTLn3 control cells. ZBP1 cells also show decreased orientation towards vessels than cells in tumors generated by MTLn3 control cells (^*P=0.0003, error bars indicate ± s.e.m.).