LXY3 (LXY2) is a VLA-3 blocking peptide that inhibits the interaction of neutrophil surface integrin α3β1 (VLA-3) with laminin in the basement membrane, thereby preventing neutrophil migration across the tumor vascular basement membrane barrier. LXY3 is employed to block the neutrophil-mediated release of nanoparticles from the perivascular pool into the tumor stroma and is frequently used for targeted imaging in breast cancer.