TM6SF2 and fatty liver disease: Genetic variations in PNPLA3, transmembrane 6 superfamily 2 (TM6SF2), membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), or other genes associated with hepatic steatosis may possibly explain the relationship between lean NAFLD and the increased future risk of developing severe liver disease or RFS in HCC.