CXCL12 and colorectal carcinoma: CXCL12 production in the early stage of CRC may assist angiogenesis and the growth of tumour cells, while in subsequent stages, CXCL12 production is lower, in order to avoid the recruitment of cytotoxic lymphocytes and enhancing the metastatic potential of the CRC tumour cells towards sites producing high levels of CXCL12 [19].