Strong epidemiological links between MASLD, insulin resistance and T2DM exist: T2DM is associated with higher prevalence and severity of MASLD, up to hepatic decompensation and hepatocellular carcinoma, and MASLD is in turn associated with incident T2DM Mechanistic studies support insulin resistance of metabolic tissues as the root cause of MASLD, whereas hepatic insulin resistance in turn contributes to hyperglycemia. This evidence concerns the gene INS and type 2 diabetes mellitus.