EC motility within vascular guidance tunnels is an MMP-independent process. Nuclear GFP-ECs were allowed to undergo morphogenesis in 3D collagen matrices for 48 hours to establish a network of tubes and vascular guidance tunnels. At 48 hours, GM6001 was either added or not to block further proteolysis and time-lapse imaging done. (A) Tracking of nuclei was done and representative tracings of cellular movement are shown. (B-C) Quantification of EC total distance traveled and average velocity are shown, demonstrating that EC migration within vascular guidance tunnels does not depend on MMP activity.