GLG1 and neoplasm: Tumor cells can then establish firm adhesion with activated endothelial cells via expressed selectin ligands [e.g., PSGL-1, CD44v, CD24, HCELL, E-selectin ligand 1 (ESL-1); (174–178)] and integrins [e.g., α4ß1/VLA-4, αLß2/LFA-1, and α3β1; (162, 179–182)].