CXCL12 and neoplasm: In addition, CXCL14 binds to CXCR4 and inhibits CXCL12-CXCR4 signaling [19] and CXCL12 signaling mediated by CXCR4 regulates and plays an important role not only in PGC migration but also a wide range of biological phenomena and developmental processes in vertebrates; such as leukocyte chemotaxis, homing of hematopoietic cells, blood vessel formation, neuronal patterning, and tumor cell growth and metastasis [5].