This article focuses on probable mechanisms of hepatitis B virus- and
hepatitis C virus-induced hepatocellular carcinoma and includes a disc
ussion on whether the two viruses interact in hepato-cellular carcinog
enesis. Possible interactions between these viruses and alcohol abuse
in tumor development are considered as well. Although substantial prog
ress has been made in understanding the cause and pathogenesis of hepa
tocellular carcinoma, much remains to be learned.