Data from both in vivo and in vitro models showed that the CXCR2/CXCL1 axis as well as the CXCR2/CXCL5 axis regulate neutrophil infiltration into tumor tissues, inducing epithelial–mesenchymal transition and thus aggravating malignant behavior of HCC cells [24,47,48]. The gene discussed is CXCR2; the disease is hepatocellular carcinoma.