Marques et al. (2021) used liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) to analyze serum samples from patients with NAFL and NASH, which showed that serum leptin levels were proportional to hepatic lipid accumulation and that leptin can be used as a potential biomarker for non-invasive diagnosis of NAFLD. This evidence concerns the gene LEP and metabolic dysfunction-associated steatohepatitis.