CXCR4 and breast carcinoma: Recent studies confirmed the necessity of CXCR4 in breast cancer metastasis [3] and imaging studies demonstrated that CXCR4 is required to initiate the proliferation and/or promote survival of breast cancer cells in vivo and suggest that CXCR4 inhibitors, such as; 1,1′-[1,4-Phenylenebis(methylene)]bis(1,4,8,11-tetraazacyclotetradecane) (AMD3100; Plerixafor), can improve the treatment of patients with primary and metastatic breast cancers [4].