CXCR4 and breast cancer: With the exception of the MDA-MB-468 CXCR4 negative breast cancer cells, all other cell types (Jurkats, THP-1s, HUVECs, breast cancer cells (MCF-7, MCF-10A, MDA-MB-231 and 468 “CXCR4 knock ins”) had slight variations in surface receptor expression (within 3-fold).