ACKR3 and cancer: There are four families of chemokines, CXC, CC, CX3C, and C. Among them, CXC ligand 12 (CXCL12) of the CXC chemokines family, was previously shown to have important impact on the proliferation and invasion of many types of cancer cells, through its specific receptors CXCR4 (12) CXCR7 (13).