Is smoking causally-associated with hepatitis B virus-related hepatocellular carcinoma?

Hepatitis B virus (HBV) is by far the strongest risk factor for the development of hepatocellular carcinoma (HCC). This effect seems to be augmented with several environmental factors. For instance, alcohol consumption was proved to play an important role and much attention was paid to understand the underlying mechanisms (1). On the other hand, the role of smoking was less studied despite the availability of several case-control studies that associate smoking with the risk of development HCC. This might be due to lack of clear mechanistic studies explain this effect.