ADH4 and alcoholic fatty liver disease: Additionally, the expression of alcohol dehydrogenase 4 (ADH4) was significantly reduced to 30% of controls, and an induced expression of ADH4 has been implicated in ROS-mediated DNA damage in both alcoholic and non-alcoholic steatohepatitis [142,143], while its deficiency impairs the metabolism of retinol to retinoic acid.