CXCL12 and neoplasm: Additionally, CXCR4 expression in tumor cells was associated with metastasis of many human malignancies (Muller et al., 2001; Ben-Baruch, 2008; Zlotnik, 2008; Ferrari et al., 2012) favoring their migration and homing toward CXCL12 expressing organs (lung, liver, brain, lymph nodes, bone marrow; Teicher and Fricker, 2010).