Evidence in support of this is: (i) mice lacking the hepatocyte insulin receptor had marked insulin resistance and dysglycemia and did not develop MASLD even when challenged with a HFD [115]; and (ii) human subjects with mutations in the insulin receptor gene or inhibitory antibodies specific for the insulin receptor had insulin resistance and hyperglycemia without hepatic steatosis [114]. This evidence concerns the gene INSR and metabolic dysfunction-associated steatotic liver disease.