CXCR4 and cancer: Dataobtained from in vitro as well as from murine in vivo models, analyzing themetastatic ability of CXCR4 in expressing cancer cells, underlined thekey role of CXCR4 for tumor cell malignancy, as activation of CXCR4 by SDF-1α induced migration, invasion, and angiogenesis of cancercells [21–23].