CXCR4 and breast carcinoma: For example, CXCR4 (Chemokine (C-X-C motif) receptor 4) has been implicated in breast [31] and colon cancer metastasis.[32] LOX (lysyl oxidase) was shown to be associated with hypoxia where it functions in metastasis and predicts poor outcome in breast cancer.[33] SPARC (secreted protein, acidic, cysteine-rich; osteonectin) was identified among genes that mark and mediate breast cancer metastasis.[34] Further studies are needed to characterize these and other signature genes in CRC progression.