CXCR4 is a chemokine receptor often overexpressed in cancer cells and involved with metastasis. N2,N6-Bis(L-lysylglycyl-L-valyl-L-seryl-L-leucyl-L-seryl-L-tyrosyl-L-arginyl)-L-lysinamide is a CXCR4 antagonist. It inhibits ovarian cancer cell migration to CXCL12 and induces cell death in CXCR4-positive cells.