CX3CL1 and hepatitis B virus infection: This in vitro evidence was confirmed in vivo by Matsubara et al. who found that cirrhotic hepatitis B HCC patients who have a high expression of fractalkine and its receptor CX3CR1 have also a low rate of recurrence of intrahepatic or extrahepatic metastases, which suggest that their expression may be related to the prognosis of HCC patients, and may be involved in tumor immunity by killing tumor cells [27].