CXCR7 is expressed in activated endothelial cells, tumor cell lines, early fetal liver cells, transforming cells (Burns et al., 2006[6]), migrating primordium in zebrafish (Dambly-Chaudiere et al., 2007[9]), monocytes, human fetal heart, neuronal tissue, adult mouse cerebellum, mature B cells (Infantino et al., 2006[21]; Thelen and Thelen, 2008[58]), blood and lymphatic endothelial cells in human renal allografts (Neusser et al., 2010[39]). Here, ACKR3 is linked to neoplasm.