TM6SF2 and fatty liver disease: Furthermore, a study evaluating the combined effect of PNPLA3 and TM6SF2 polymorphisms in NAFLD found variants of PNPLA3 and TM6SF2 to be independently associated with hepatic steatosis, while PNPLA3 but not TM6SF2 was associated with liver fibrosis in a multivariable model.