E70K is a compound that inhibits the interaction between the chemokine (C-X-C) ligand 8 (CXCL8) and glycosaminoglycans (GAGs) on cell membrane surfaces. It mimics a segment of the CXCL8 protein's GAG-binding region at the C-terminal end, incorporating a glutamate-to-lysine mutation at the 70th position. At a concentration of 50 nM, E70K notably reduces the attachment of primary human neutrophils to human umbilical vein endothelial cells (HUVECs). Moreover, it impedes the CXCL8-triggered movement of these neutrophils across HMEC-1 human microvascular endothelial cell layers within a concentration range of 1 to 1,000 nM.