CXCR4 and breast carcinoma: Taking into account the relevant oncogenic role of the CXCR4/CXCL12 axis in breast cancer progression and its potential to be targeted by anti-tumor molecules, we aimed to clarify the signature of CXCR4 and CXCL12 in cats with mammary metastatic disease and search for significant associations between CXCR4 and CXCL12 tissue status and serum CXCL12 values, clinicopathological features and FMC molecular subtypes.