CXCR4 and malignant colon neoplasm: By evaluating histological samples from human colon cancer metastases in the liver, we observed that numerous HB-EGF/CXCR4-positive macrophages, which expressed both the M1 CXCL10 and the M2 CD163 markers, indicating a mixed M1/M2 microenvironment, infiltrated metastatic cancer cells.