Most recently, an observational study in middle-aged adults showed that the serum IL-15 levels of obese patients with NAFLD were higher than those of healthy subjects and associated with the levels of monocyte chemoattractant protein-1 (Mcp-1) and the granulocyte-macrophage colony-stimulating factor (GM-CSF), which are well-known inflammatory biomarkers. This evidence concerns the gene IL15 and metabolic dysfunction-associated steatotic liver disease.