Other conditions associated with steatosis are insulin resistance and glucose intolerance.1, 6 On the molecular level, insulin resistance is characterized by defects in IR signaling, which is observed upon the hepatocyte-specific deletion of the GH receptor or STAT5,3, 4 but not upon ablation of hepatic JAK2.16 Insulin resistance might be explained by observations made by others and similarly by us as follows. This evidence concerns the gene JAK2 and steatosis.