Importantly, we observed an interesting phenomenon that IL-8 treatment only promoted the apoptosis of HepG2 cells co-cultured with THP-1 cells of the scramble control group, which express high level of CXCR2 and simulate circulating monocytes of healthy controls; while in the THP-1 cells with CXCR2 knock-down, which simulates the monocytes of HCC patients, the regulatory effect of IL-8 on the cytotoxicity towards HepG2 was lost. Here, CXCR2 is linked to hepatocellular carcinoma.