CXCR4 and hepatocellular carcinoma: These results demonstrate that the PPIAP22/miR-197-3p/PPIA axis might not only induce the malignancy of tumor cells through CCL15-CCR1 and CXCL12-CXCR4/CXCR7 pathways but also regulate the macrophage infiltration in HCC by recruiting monocytes through CCL15-CCR1 and CXCL12-CXCR4/CXCR7 pathways.