(C) EC were seeded on gelatin-coated Transwell inserts. RFP-labeled LLC cells were allowed to transmigrate for 8 h through the endothelial layer. Thereafter, transmigrated tumor cells were counted. The dot plot presents the normalized data (mean ± SD, n = 9 inserts from three independent experiments). ***, P<0.001 (two-tailed Mann-Whitney U test). 